move-contrib-v3.patch

diff --git a/contrib/Makefile b/contrib/Makefile
index 6967767..bcb9465 100644
--- a/contrib/Makefile
+++ b/contrib/Makefile
@@ -7,7 +7,6 @@ include $(top_builddir)/src/Makefile.global
 SUBDIRS = \
 		adminpack	\
 		auth_delay	\
-		auto_explain	\
 		btree_gin	\
 		btree_gist	\
 		chkpass		\
@@ -27,21 +26,15 @@ SUBDIRS = \
 		lo		\
 		ltree		\
 		oid2name	\
-		pageinspect	\
 		passwordcheck	\
 		pg_archivecleanup \
-		pg_buffercache	\
-		pg_freespacemap \
 		pg_standby	\
-		pg_stat_statements \
 		pg_test_fsync	\
 		pg_trgm		\
 		pg_upgrade	\
 		pg_upgrade_support \
 		pgbench		\
 		pgcrypto	\
-		pgrowlocks	\
-		pgstattuple	\
 		seg		\
 		spi		\
 		tablefunc	\
diff --git a/contrib/auto_explain/Makefile b/contrib/auto_explain/Makefile
deleted file mode 100644
index 2d1443f..0000000
--- a/contrib/auto_explain/Makefile
+++ /dev/null
@@ -1,15 +0,0 @@
-# contrib/auto_explain/Makefile
-
-MODULE_big = auto_explain
-OBJS = auto_explain.o
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/auto_explain
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
diff --git a/contrib/auto_explain/auto_explain.c b/contrib/auto_explain/auto_explain.c
deleted file mode 100644
index b320698..0000000
--- a/contrib/auto_explain/auto_explain.c
+++ /dev/null
@@ -1,304 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * auto_explain.c
- *
- *
- * Copyright (c) 2008-2011, PostgreSQL Global Development Group
- *
- * IDENTIFICATION
- *	  contrib/auto_explain/auto_explain.c
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include "commands/explain.h"
-#include "executor/instrument.h"
-#include "utils/guc.h"
-
-PG_MODULE_MAGIC;
-
-/* GUC variables */
-static int	auto_explain_log_min_duration = -1; /* msec or -1 */
-static bool auto_explain_log_analyze = false;
-static bool auto_explain_log_verbose = false;
-static bool auto_explain_log_buffers = false;
-static int	auto_explain_log_format = EXPLAIN_FORMAT_TEXT;
-static bool auto_explain_log_nested_statements = false;
-
-static const struct config_enum_entry format_options[] = {
-	{"text", EXPLAIN_FORMAT_TEXT, false},
-	{"xml", EXPLAIN_FORMAT_XML, false},
-	{"json", EXPLAIN_FORMAT_JSON, false},
-	{"yaml", EXPLAIN_FORMAT_YAML, false},
-	{NULL, 0, false}
-};
-
-/* Current nesting depth of ExecutorRun calls */
-static int	nesting_level = 0;
-
-/* Saved hook values in case of unload */
-static ExecutorStart_hook_type prev_ExecutorStart = NULL;
-static ExecutorRun_hook_type prev_ExecutorRun = NULL;
-static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
-static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
-
-#define auto_explain_enabled() \
-	(auto_explain_log_min_duration >= 0 && \
-	 (nesting_level == 0 || auto_explain_log_nested_statements))
-
-void		_PG_init(void);
-void		_PG_fini(void);
-
-static void explain_ExecutorStart(QueryDesc *queryDesc, int eflags);
-static void explain_ExecutorRun(QueryDesc *queryDesc,
-					ScanDirection direction,
-					long count);
-static void explain_ExecutorFinish(QueryDesc *queryDesc);
-static void explain_ExecutorEnd(QueryDesc *queryDesc);
-
-
-/*
- * Module load callback
- */
-void
-_PG_init(void)
-{
-	/* Define custom GUC variables. */
-	DefineCustomIntVariable("auto_explain.log_min_duration",
-		 "Sets the minimum execution time above which plans will be logged.",
-						 "Zero prints all plans. -1 turns this feature off.",
-							&auto_explain_log_min_duration,
-							-1,
-							-1, INT_MAX / 1000,
-							PGC_SUSET,
-							GUC_UNIT_MS,
-							NULL,
-							NULL,
-							NULL);
-
-	DefineCustomBoolVariable("auto_explain.log_analyze",
-							 "Use EXPLAIN ANALYZE for plan logging.",
-							 NULL,
-							 &auto_explain_log_analyze,
-							 false,
-							 PGC_SUSET,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	DefineCustomBoolVariable("auto_explain.log_verbose",
-							 "Use EXPLAIN VERBOSE for plan logging.",
-							 NULL,
-							 &auto_explain_log_verbose,
-							 false,
-							 PGC_SUSET,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	DefineCustomBoolVariable("auto_explain.log_buffers",
-							 "Log buffers usage.",
-							 NULL,
-							 &auto_explain_log_buffers,
-							 false,
-							 PGC_SUSET,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	DefineCustomEnumVariable("auto_explain.log_format",
-							 "EXPLAIN format to be used for plan logging.",
-							 NULL,
-							 &auto_explain_log_format,
-							 EXPLAIN_FORMAT_TEXT,
-							 format_options,
-							 PGC_SUSET,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	DefineCustomBoolVariable("auto_explain.log_nested_statements",
-							 "Log nested statements.",
-							 NULL,
-							 &auto_explain_log_nested_statements,
-							 false,
-							 PGC_SUSET,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	EmitWarningsOnPlaceholders("auto_explain");
-
-	/* Install hooks. */
-	prev_ExecutorStart = ExecutorStart_hook;
-	ExecutorStart_hook = explain_ExecutorStart;
-	prev_ExecutorRun = ExecutorRun_hook;
-	ExecutorRun_hook = explain_ExecutorRun;
-	prev_ExecutorFinish = ExecutorFinish_hook;
-	ExecutorFinish_hook = explain_ExecutorFinish;
-	prev_ExecutorEnd = ExecutorEnd_hook;
-	ExecutorEnd_hook = explain_ExecutorEnd;
-}
-
-/*
- * Module unload callback
- */
-void
-_PG_fini(void)
-{
-	/* Uninstall hooks. */
-	ExecutorStart_hook = prev_ExecutorStart;
-	ExecutorRun_hook = prev_ExecutorRun;
-	ExecutorFinish_hook = prev_ExecutorFinish;
-	ExecutorEnd_hook = prev_ExecutorEnd;
-}
-
-/*
- * ExecutorStart hook: start up logging if needed
- */
-static void
-explain_ExecutorStart(QueryDesc *queryDesc, int eflags)
-{
-	if (auto_explain_enabled())
-	{
-		/* Enable per-node instrumentation iff log_analyze is required. */
-		if (auto_explain_log_analyze && (eflags & EXEC_FLAG_EXPLAIN_ONLY) == 0)
-		{
-			queryDesc->instrument_options |= INSTRUMENT_TIMER;
-			if (auto_explain_log_buffers)
-				queryDesc->instrument_options |= INSTRUMENT_BUFFERS;
-		}
-	}
-
-	if (prev_ExecutorStart)
-		prev_ExecutorStart(queryDesc, eflags);
-	else
-		standard_ExecutorStart(queryDesc, eflags);
-
-	if (auto_explain_enabled())
-	{
-		/*
-		 * Set up to track total elapsed time in ExecutorRun.  Make sure the
-		 * space is allocated in the per-query context so it will go away at
-		 * ExecutorEnd.
-		 */
-		if (queryDesc->totaltime == NULL)
-		{
-			MemoryContext oldcxt;
-
-			oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
-			queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL);
-			MemoryContextSwitchTo(oldcxt);
-		}
-	}
-}
-
-/*
- * ExecutorRun hook: all we need do is track nesting depth
- */
-static void
-explain_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count)
-{
-	nesting_level++;
-	PG_TRY();
-	{
-		if (prev_ExecutorRun)
-			prev_ExecutorRun(queryDesc, direction, count);
-		else
-			standard_ExecutorRun(queryDesc, direction, count);
-		nesting_level--;
-	}
-	PG_CATCH();
-	{
-		nesting_level--;
-		PG_RE_THROW();
-	}
-	PG_END_TRY();
-}
-
-/*
- * ExecutorFinish hook: all we need do is track nesting depth
- */
-static void
-explain_ExecutorFinish(QueryDesc *queryDesc)
-{
-	nesting_level++;
-	PG_TRY();
-	{
-		if (prev_ExecutorFinish)
-			prev_ExecutorFinish(queryDesc);
-		else
-			standard_ExecutorFinish(queryDesc);
-		nesting_level--;
-	}
-	PG_CATCH();
-	{
-		nesting_level--;
-		PG_RE_THROW();
-	}
-	PG_END_TRY();
-}
-
-/*
- * ExecutorEnd hook: log results if needed
- */
-static void
-explain_ExecutorEnd(QueryDesc *queryDesc)
-{
-	if (queryDesc->totaltime && auto_explain_enabled())
-	{
-		double		msec;
-
-		/*
-		 * Make sure stats accumulation is done.  (Note: it's okay if several
-		 * levels of hook all do this.)
-		 */
-		InstrEndLoop(queryDesc->totaltime);
-
-		/* Log plan if duration is exceeded. */
-		msec = queryDesc->totaltime->total * 1000.0;
-		if (msec >= auto_explain_log_min_duration)
-		{
-			ExplainState es;
-
-			ExplainInitState(&es);
-			es.analyze = (queryDesc->instrument_options && auto_explain_log_analyze);
-			es.verbose = auto_explain_log_verbose;
-			es.buffers = (es.analyze && auto_explain_log_buffers);
-			es.format = auto_explain_log_format;
-
-			ExplainBeginOutput(&es);
-			ExplainQueryText(&es, queryDesc);
-			ExplainPrintPlan(&es, queryDesc);
-			ExplainEndOutput(&es);
-
-			/* Remove last line break */
-			if (es.str->len > 0 && es.str->data[es.str->len - 1] == '\n')
-				es.str->data[--es.str->len] = '\0';
-
-			/*
-			 * Note: we rely on the existing logging of context or
-			 * debug_query_string to identify just which statement is being
-			 * reported.  This isn't ideal but trying to do it here would
-			 * often result in duplication.
-			 */
-			ereport(LOG,
-					(errmsg("duration: %.3f ms  plan:\n%s",
-							msec, es.str->data),
-					 errhidestmt(true)));
-
-			pfree(es.str->data);
-		}
-	}
-
-	if (prev_ExecutorEnd)
-		prev_ExecutorEnd(queryDesc);
-	else
-		standard_ExecutorEnd(queryDesc);
-}
diff --git a/contrib/pageinspect/Makefile b/contrib/pageinspect/Makefile
deleted file mode 100644
index 13ba6d3..0000000
--- a/contrib/pageinspect/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-# contrib/pageinspect/Makefile
-
-MODULE_big	= pageinspect
-OBJS		= rawpage.o heapfuncs.o btreefuncs.o fsmfuncs.o
-
-EXTENSION = pageinspect
-DATA = pageinspect--1.0.sql pageinspect--unpackaged--1.0.sql
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/pageinspect
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
diff --git a/contrib/pageinspect/btreefuncs.c b/contrib/pageinspect/btreefuncs.c
deleted file mode 100644
index ef27cd4..0000000
--- a/contrib/pageinspect/btreefuncs.c
+++ /dev/null
@@ -1,502 +0,0 @@
-/*
- * contrib/pageinspect/btreefuncs.c
- *
- *
- * btreefuncs.c
- *
- * Copyright (c) 2006 Satoshi Nagayasu <nagayasus@nttdata.co.jp>
- *
- * Permission to use, copy, modify, and distribute this software and
- * its documentation for any purpose, without fee, and without a
- * written agreement is hereby granted, provided that the above
- * copyright notice and this paragraph and the following two
- * paragraphs appear in all copies.
- *
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
- * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
- * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
- * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
- * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
- * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- */
-
-#include "postgres.h"
-
-#include "access/heapam.h"
-#include "access/nbtree.h"
-#include "catalog/namespace.h"
-#include "catalog/pg_type.h"
-#include "funcapi.h"
-#include "miscadmin.h"
-#include "storage/bufmgr.h"
-#include "utils/builtins.h"
-
-
-extern Datum bt_metap(PG_FUNCTION_ARGS);
-extern Datum bt_page_items(PG_FUNCTION_ARGS);
-extern Datum bt_page_stats(PG_FUNCTION_ARGS);
-
-PG_FUNCTION_INFO_V1(bt_metap);
-PG_FUNCTION_INFO_V1(bt_page_items);
-PG_FUNCTION_INFO_V1(bt_page_stats);
-
-#define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
-#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
-
-#define CHECK_PAGE_OFFSET_RANGE(pg, offnum) { \
-		if ( !(FirstOffsetNumber <= (offnum) && \
-						(offnum) <= PageGetMaxOffsetNumber(pg)) ) \
-			 elog(ERROR, "page offset number out of range"); }
-
-/* note: BlockNumber is unsigned, hence can't be negative */
-#define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
-		if ( RelationGetNumberOfBlocks(rel) <= (BlockNumber) (blkno) ) \
-			 elog(ERROR, "block number out of range"); }
-
-/* ------------------------------------------------
- * structure for single btree page statistics
- * ------------------------------------------------
- */
-typedef struct BTPageStat
-{
-	uint32		blkno;
-	uint32		live_items;
-	uint32		dead_items;
-	uint32		page_size;
-	uint32		max_avail;
-	uint32		free_size;
-	uint32		avg_item_size;
-	char		type;
-
-	/* opaque data */
-	BlockNumber btpo_prev;
-	BlockNumber btpo_next;
-	union
-	{
-		uint32		level;
-		TransactionId xact;
-	}			btpo;
-	uint16		btpo_flags;
-	BTCycleId	btpo_cycleid;
-} BTPageStat;
-
-
-/* -------------------------------------------------
- * GetBTPageStatistics()
- *
- * Collect statistics of single b-tree page
- * -------------------------------------------------
- */
-static void
-GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat *stat)
-{
-	Page		page = BufferGetPage(buffer);
-	PageHeader	phdr = (PageHeader) page;
-	OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
-	BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
-	int			item_size = 0;
-	int			off;
-
-	stat->blkno = blkno;
-
-	stat->max_avail = BLCKSZ - (BLCKSZ - phdr->pd_special + SizeOfPageHeaderData);
-
-	stat->dead_items = stat->live_items = 0;
-
-	stat->page_size = PageGetPageSize(page);
-
-	/* page type (flags) */
-	if (P_ISDELETED(opaque))
-	{
-		stat->type = 'd';
-		stat->btpo.xact = opaque->btpo.xact;
-		return;
-	}
-	else if (P_IGNORE(opaque))
-		stat->type = 'e';
-	else if (P_ISLEAF(opaque))
-		stat->type = 'l';
-	else if (P_ISROOT(opaque))
-		stat->type = 'r';
-	else
-		stat->type = 'i';
-
-	/* btpage opaque data */
-	stat->btpo_prev = opaque->btpo_prev;
-	stat->btpo_next = opaque->btpo_next;
-	stat->btpo.level = opaque->btpo.level;
-	stat->btpo_flags = opaque->btpo_flags;
-	stat->btpo_cycleid = opaque->btpo_cycleid;
-
-	/* count live and dead tuples, and free space */
-	for (off = FirstOffsetNumber; off <= maxoff; off++)
-	{
-		IndexTuple	itup;
-
-		ItemId		id = PageGetItemId(page, off);
-
-		itup = (IndexTuple) PageGetItem(page, id);
-
-		item_size += IndexTupleSize(itup);
-
-		if (!ItemIdIsDead(id))
-			stat->live_items++;
-		else
-			stat->dead_items++;
-	}
-	stat->free_size = PageGetFreeSpace(page);
-
-	if ((stat->live_items + stat->dead_items) > 0)
-		stat->avg_item_size = item_size / (stat->live_items + stat->dead_items);
-	else
-		stat->avg_item_size = 0;
-}
-
-/* -----------------------------------------------
- * bt_page()
- *
- * Usage: SELECT * FROM bt_page('t1_pkey', 1);
- * -----------------------------------------------
- */
-Datum
-bt_page_stats(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	uint32		blkno = PG_GETARG_UINT32(1);
-	Buffer		buffer;
-	Relation	rel;
-	RangeVar   *relrv;
-	Datum		result;
-	HeapTuple	tuple;
-	TupleDesc	tupleDesc;
-	int			j;
-	char	   *values[11];
-	BTPageStat	stat;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use pageinspect functions"))));
-
-	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-	rel = relation_openrv(relrv, AccessShareLock);
-
-	if (!IS_INDEX(rel) || !IS_BTREE(rel))
-		elog(ERROR, "relation \"%s\" is not a btree index",
-			 RelationGetRelationName(rel));
-
-	/*
-	 * Reject attempts to read non-local temporary relations; we would be
-	 * likely to get wrong data since we have no visibility into the owning
-	 * session's local buffers.
-	 */
-	if (RELATION_IS_OTHER_TEMP(rel))
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot access temporary tables of other sessions")));
-
-	if (blkno == 0)
-		elog(ERROR, "block 0 is a meta page");
-
-	CHECK_RELATION_BLOCK_RANGE(rel, blkno);
-
-	buffer = ReadBuffer(rel, blkno);
-
-	/* keep compiler quiet */
-	stat.btpo_prev = stat.btpo_next = InvalidBlockNumber;
-	stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;
-
-	GetBTPageStatistics(blkno, buffer, &stat);
-
-	/* Build a tuple descriptor for our result type */
-	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
-		elog(ERROR, "return type must be a row type");
-
-	j = 0;
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.blkno);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%c", stat.type);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.live_items);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.dead_items);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.avg_item_size);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.page_size);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.free_size);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.btpo_prev);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.btpo_next);
-	values[j] = palloc(32);
-	if (stat.type == 'd')
-		snprintf(values[j++], 32, "%d", stat.btpo.xact);
-	else
-		snprintf(values[j++], 32, "%d", stat.btpo.level);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", stat.btpo_flags);
-
-	tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
-								   values);
-
-	result = HeapTupleGetDatum(tuple);
-
-	ReleaseBuffer(buffer);
-
-	relation_close(rel, AccessShareLock);
-
-	PG_RETURN_DATUM(result);
-}
-
-/*-------------------------------------------------------
- * bt_page_items()
- *
- * Get IndexTupleData set in a btree page
- *
- * Usage: SELECT * FROM bt_page_items('t1_pkey', 1);
- *-------------------------------------------------------
- */
-
-/*
- * cross-call data structure for SRF
- */
-struct user_args
-{
-	Page		page;
-	OffsetNumber offset;
-};
-
-Datum
-bt_page_items(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	uint32		blkno = PG_GETARG_UINT32(1);
-	Datum		result;
-	char	   *values[6];
-	HeapTuple	tuple;
-	FuncCallContext *fctx;
-	MemoryContext mctx;
-	struct user_args *uargs;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use pageinspect functions"))));
-
-	if (SRF_IS_FIRSTCALL())
-	{
-		RangeVar   *relrv;
-		Relation	rel;
-		Buffer		buffer;
-		BTPageOpaque opaque;
-		TupleDesc	tupleDesc;
-
-		fctx = SRF_FIRSTCALL_INIT();
-
-		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-		rel = relation_openrv(relrv, AccessShareLock);
-
-		if (!IS_INDEX(rel) || !IS_BTREE(rel))
-			elog(ERROR, "relation \"%s\" is not a btree index",
-				 RelationGetRelationName(rel));
-
-		/*
-		 * Reject attempts to read non-local temporary relations; we would be
-		 * likely to get wrong data since we have no visibility into the
-		 * owning session's local buffers.
-		 */
-		if (RELATION_IS_OTHER_TEMP(rel))
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				errmsg("cannot access temporary tables of other sessions")));
-
-		if (blkno == 0)
-			elog(ERROR, "block 0 is a meta page");
-
-		CHECK_RELATION_BLOCK_RANGE(rel, blkno);
-
-		buffer = ReadBuffer(rel, blkno);
-
-		/*
-		 * We copy the page into local storage to avoid holding pin on the
-		 * buffer longer than we must, and possibly failing to release it at
-		 * all if the calling query doesn't fetch all rows.
-		 */
-		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
-
-		uargs = palloc(sizeof(struct user_args));
-
-		uargs->page = palloc(BLCKSZ);
-		memcpy(uargs->page, BufferGetPage(buffer), BLCKSZ);
-
-		ReleaseBuffer(buffer);
-		relation_close(rel, AccessShareLock);
-
-		uargs->offset = FirstOffsetNumber;
-
-		opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page);
-
-		if (P_ISDELETED(opaque))
-			elog(NOTICE, "page is deleted");
-
-		fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
-
-		/* Build a tuple descriptor for our result type */
-		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
-			elog(ERROR, "return type must be a row type");
-
-		fctx->attinmeta = TupleDescGetAttInMetadata(tupleDesc);
-
-		fctx->user_fctx = uargs;
-
-		MemoryContextSwitchTo(mctx);
-	}
-
-	fctx = SRF_PERCALL_SETUP();
-	uargs = fctx->user_fctx;
-
-	if (fctx->call_cntr < fctx->max_calls)
-	{
-		ItemId		id;
-		IndexTuple	itup;
-		int			j;
-		int			off;
-		int			dlen;
-		char	   *dump;
-		char	   *ptr;
-
-		id = PageGetItemId(uargs->page, uargs->offset);
-
-		if (!ItemIdIsValid(id))
-			elog(ERROR, "invalid ItemId");
-
-		itup = (IndexTuple) PageGetItem(uargs->page, id);
-
-		j = 0;
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%d", uargs->offset);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "(%u,%u)",
-				 BlockIdGetBlockNumber(&(itup->t_tid.ip_blkid)),
-				 itup->t_tid.ip_posid);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%d", (int) IndexTupleSize(itup));
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%c", IndexTupleHasNulls(itup) ? 't' : 'f');
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');
-
-		ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
-		dlen = IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
-		dump = palloc0(dlen * 3 + 1);
-		values[j] = dump;
-		for (off = 0; off < dlen; off++)
-		{
-			if (off > 0)
-				*dump++ = ' ';
-			sprintf(dump, "%02x", *(ptr + off) & 0xff);
-			dump += 2;
-		}
-
-		tuple = BuildTupleFromCStrings(fctx->attinmeta, values);
-		result = HeapTupleGetDatum(tuple);
-
-		uargs->offset = uargs->offset + 1;
-
-		SRF_RETURN_NEXT(fctx, result);
-	}
-	else
-	{
-		pfree(uargs->page);
-		pfree(uargs);
-		SRF_RETURN_DONE(fctx);
-	}
-}
-
-
-/* ------------------------------------------------
- * bt_metap()
- *
- * Get a btree's meta-page information
- *
- * Usage: SELECT * FROM bt_metap('t1_pkey')
- * ------------------------------------------------
- */
-Datum
-bt_metap(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	Datum		result;
-	Relation	rel;
-	RangeVar   *relrv;
-	BTMetaPageData *metad;
-	TupleDesc	tupleDesc;
-	int			j;
-	char	   *values[6];
-	Buffer		buffer;
-	Page		page;
-	HeapTuple	tuple;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use pageinspect functions"))));
-
-	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-	rel = relation_openrv(relrv, AccessShareLock);
-
-	if (!IS_INDEX(rel) || !IS_BTREE(rel))
-		elog(ERROR, "relation \"%s\" is not a btree index",
-			 RelationGetRelationName(rel));
-
-	/*
-	 * Reject attempts to read non-local temporary relations; we would be
-	 * likely to get wrong data since we have no visibility into the owning
-	 * session's local buffers.
-	 */
-	if (RELATION_IS_OTHER_TEMP(rel))
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot access temporary tables of other sessions")));
-
-	buffer = ReadBuffer(rel, 0);
-	page = BufferGetPage(buffer);
-	metad = BTPageGetMeta(page);
-
-	/* Build a tuple descriptor for our result type */
-	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
-		elog(ERROR, "return type must be a row type");
-
-	j = 0;
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", metad->btm_magic);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", metad->btm_version);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", metad->btm_root);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", metad->btm_level);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", metad->btm_fastroot);
-	values[j] = palloc(32);
-	snprintf(values[j++], 32, "%d", metad->btm_fastlevel);
-
-	tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
-								   values);
-
-	result = HeapTupleGetDatum(tuple);
-
-	ReleaseBuffer(buffer);
-
-	relation_close(rel, AccessShareLock);
-
-	PG_RETURN_DATUM(result);
-}
diff --git a/contrib/pageinspect/fsmfuncs.c b/contrib/pageinspect/fsmfuncs.c
deleted file mode 100644
index 38c4e23..0000000
--- a/contrib/pageinspect/fsmfuncs.c
+++ /dev/null
@@ -1,59 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * fsmfuncs.c
- *	  Functions to investigate FSM pages
- *
- * These functions are restricted to superusers for the fear of introducing
- * security holes if the input checking isn't as water-tight as it should.
- * You'd need to be superuser to obtain a raw page image anyway, so
- * there's hardly any use case for using these without superuser-rights
- * anyway.
- *
- * Copyright (c) 2007-2011, PostgreSQL Global Development Group
- *
- * IDENTIFICATION
- *	  contrib/pageinspect/fsmfuncs.c
- *
- *-------------------------------------------------------------------------
- */
-
-#include "postgres.h"
-#include "lib/stringinfo.h"
-#include "storage/fsm_internals.h"
-#include "utils/builtins.h"
-#include "miscadmin.h"
-#include "funcapi.h"
-
-Datum		fsm_page_contents(PG_FUNCTION_ARGS);
-
-/*
- * Dumps the contents of a FSM page.
- */
-PG_FUNCTION_INFO_V1(fsm_page_contents);
-
-Datum
-fsm_page_contents(PG_FUNCTION_ARGS)
-{
-	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
-	StringInfoData sinfo;
-	FSMPage		fsmpage;
-	int			i;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use raw page functions"))));
-
-	fsmpage = (FSMPage) PageGetContents(VARDATA(raw_page));
-
-	initStringInfo(&sinfo);
-
-	for (i = 0; i < NodesPerPage; i++)
-	{
-		if (fsmpage->fp_nodes[i] != 0)
-			appendStringInfo(&sinfo, "%d: %d\n", i, fsmpage->fp_nodes[i]);
-	}
-	appendStringInfo(&sinfo, "fp_next_slot: %d\n", fsmpage->fp_next_slot);
-
-	PG_RETURN_TEXT_P(cstring_to_text(sinfo.data));
-}
diff --git a/contrib/pageinspect/heapfuncs.c b/contrib/pageinspect/heapfuncs.c
deleted file mode 100644
index 20bca0d..0000000
--- a/contrib/pageinspect/heapfuncs.c
+++ /dev/null
@@ -1,230 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * heapfuncs.c
- *	  Functions to investigate heap pages
- *
- * We check the input to these functions for corrupt pointers etc. that
- * might cause crashes, but at the same time we try to print out as much
- * information as possible, even if it's nonsense. That's because if a
- * page is corrupt, we don't know why and how exactly it is corrupt, so we
- * let the user judge it.
- *
- * These functions are restricted to superusers for the fear of introducing
- * security holes if the input checking isn't as water-tight as it should be.
- * You'd need to be superuser to obtain a raw page image anyway, so
- * there's hardly any use case for using these without superuser-rights
- * anyway.
- *
- * Copyright (c) 2007-2011, PostgreSQL Global Development Group
- *
- * IDENTIFICATION
- *	  contrib/pageinspect/heapfuncs.c
- *
- *-------------------------------------------------------------------------
- */
-
-#include "postgres.h"
-
-#include "fmgr.h"
-#include "funcapi.h"
-#include "access/heapam.h"
-#include "access/transam.h"
-#include "catalog/namespace.h"
-#include "catalog/pg_type.h"
-#include "utils/builtins.h"
-#include "miscadmin.h"
-
-Datum		heap_page_items(PG_FUNCTION_ARGS);
-
-
-/*
- * bits_to_text
- *
- * Converts a bits8-array of 'len' bits to a human-readable
- * c-string representation.
- */
-static char *
-bits_to_text(bits8 *bits, int len)
-{
-	int			i;
-	char	   *str;
-
-	str = palloc(len + 1);
-
-	for (i = 0; i < len; i++)
-		str[i] = (bits[(i / 8)] & (1 << (i % 8))) ? '1' : '0';
-
-	str[i] = '\0';
-
-	return str;
-}
-
-
-/*
- * heap_page_items
- *
- * Allows inspection of line pointers and tuple headers of a heap page.
- */
-PG_FUNCTION_INFO_V1(heap_page_items);
-
-typedef struct heap_page_items_state
-{
-	TupleDesc	tupd;
-	Page		page;
-	uint16		offset;
-} heap_page_items_state;
-
-Datum
-heap_page_items(PG_FUNCTION_ARGS)
-{
-	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
-	heap_page_items_state *inter_call_data = NULL;
-	FuncCallContext *fctx;
-	int			raw_page_size;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use raw page functions"))));
-
-	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
-
-	if (SRF_IS_FIRSTCALL())
-	{
-		TupleDesc	tupdesc;
-		MemoryContext mctx;
-
-		if (raw_page_size < SizeOfPageHeaderData)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				  errmsg("input page too small (%d bytes)", raw_page_size)));
-
-		fctx = SRF_FIRSTCALL_INIT();
-		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
-
-		inter_call_data = palloc(sizeof(heap_page_items_state));
-
-		/* Build a tuple descriptor for our result type */
-		if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
-			elog(ERROR, "return type must be a row type");
-
-		inter_call_data->tupd = tupdesc;
-
-		inter_call_data->offset = FirstOffsetNumber;
-		inter_call_data->page = VARDATA(raw_page);
-
-		fctx->max_calls = PageGetMaxOffsetNumber(inter_call_data->page);
-		fctx->user_fctx = inter_call_data;
-
-		MemoryContextSwitchTo(mctx);
-	}
-
-	fctx = SRF_PERCALL_SETUP();
-	inter_call_data = fctx->user_fctx;
-
-	if (fctx->call_cntr < fctx->max_calls)
-	{
-		Page		page = inter_call_data->page;
-		HeapTuple	resultTuple;
-		Datum		result;
-		ItemId		id;
-		Datum		values[13];
-		bool		nulls[13];
-		uint16		lp_offset;
-		uint16		lp_flags;
-		uint16		lp_len;
-
-		memset(nulls, 0, sizeof(nulls));
-
-		/* Extract information from the line pointer */
-
-		id = PageGetItemId(page, inter_call_data->offset);
-
-		lp_offset = ItemIdGetOffset(id);
-		lp_flags = ItemIdGetFlags(id);
-		lp_len = ItemIdGetLength(id);
-
-		values[0] = UInt16GetDatum(inter_call_data->offset);
-		values[1] = UInt16GetDatum(lp_offset);
-		values[2] = UInt16GetDatum(lp_flags);
-		values[3] = UInt16GetDatum(lp_len);
-
-		/*
-		 * We do just enough validity checking to make sure we don't reference
-		 * data outside the page passed to us. The page could be corrupt in
-		 * many other ways, but at least we won't crash.
-		 */
-		if (ItemIdHasStorage(id) &&
-			lp_len >= sizeof(HeapTupleHeader) &&
-			lp_offset == MAXALIGN(lp_offset) &&
-			lp_offset + lp_len <= raw_page_size)
-		{
-			HeapTupleHeader tuphdr;
-			int			bits_len;
-
-			/* Extract information from the tuple header */
-
-			tuphdr = (HeapTupleHeader) PageGetItem(page, id);
-
-			values[4] = UInt32GetDatum(HeapTupleHeaderGetXmin(tuphdr));
-			values[5] = UInt32GetDatum(HeapTupleHeaderGetXmax(tuphdr));
-			values[6] = UInt32GetDatum(HeapTupleHeaderGetRawCommandId(tuphdr)); /* shared with xvac */
-			values[7] = PointerGetDatum(&tuphdr->t_ctid);
-			values[8] = UInt32GetDatum(tuphdr->t_infomask2);
-			values[9] = UInt32GetDatum(tuphdr->t_infomask);
-			values[10] = UInt8GetDatum(tuphdr->t_hoff);
-
-			/*
-			 * We already checked that the item as is completely within the
-			 * raw page passed to us, with the length given in the line
-			 * pointer.. Let's check that t_hoff doesn't point over lp_len,
-			 * before using it to access t_bits and oid.
-			 */
-			if (tuphdr->t_hoff >= sizeof(HeapTupleHeader) &&
-				tuphdr->t_hoff <= lp_len)
-			{
-				if (tuphdr->t_infomask & HEAP_HASNULL)
-				{
-					bits_len = tuphdr->t_hoff -
-						(((char *) tuphdr->t_bits) -((char *) tuphdr));
-
-					values[11] = CStringGetTextDatum(
-								 bits_to_text(tuphdr->t_bits, bits_len * 8));
-				}
-				else
-					nulls[11] = true;
-
-				if (tuphdr->t_infomask & HEAP_HASOID)
-					values[12] = HeapTupleHeaderGetOid(tuphdr);
-				else
-					nulls[12] = true;
-			}
-			else
-			{
-				nulls[11] = true;
-				nulls[12] = true;
-			}
-		}
-		else
-		{
-			/*
-			 * The line pointer is not used, or it's invalid. Set the rest of
-			 * the fields to NULL
-			 */
-			int			i;
-
-			for (i = 4; i <= 12; i++)
-				nulls[i] = true;
-		}
-
-		/* Build and return the result tuple. */
-		resultTuple = heap_form_tuple(inter_call_data->tupd, values, nulls);
-		result = HeapTupleGetDatum(resultTuple);
-
-		inter_call_data->offset++;
-
-		SRF_RETURN_NEXT(fctx, result);
-	}
-	else
-		SRF_RETURN_DONE(fctx);
-}
diff --git a/contrib/pageinspect/pageinspect--1.0.sql b/contrib/pageinspect/pageinspect--1.0.sql
deleted file mode 100644
index a711f58..0000000
--- a/contrib/pageinspect/pageinspect--1.0.sql
+++ /dev/null
@@ -1,104 +0,0 @@
-/* contrib/pageinspect/pageinspect--1.0.sql */
-
---
--- get_raw_page()
---
-CREATE FUNCTION get_raw_page(text, int4)
-RETURNS bytea
-AS 'MODULE_PATHNAME', 'get_raw_page'
-LANGUAGE C STRICT;
-
-CREATE FUNCTION get_raw_page(text, text, int4)
-RETURNS bytea
-AS 'MODULE_PATHNAME', 'get_raw_page_fork'
-LANGUAGE C STRICT;
-
---
--- page_header()
---
-CREATE FUNCTION page_header(IN page bytea,
-    OUT lsn text,
-    OUT tli smallint,
-    OUT flags smallint,
-    OUT lower smallint,
-    OUT upper smallint,
-    OUT special smallint,
-    OUT pagesize smallint,
-    OUT version smallint,
-    OUT prune_xid xid)
-AS 'MODULE_PATHNAME', 'page_header'
-LANGUAGE C STRICT;
-
---
--- heap_page_items()
---
-CREATE FUNCTION heap_page_items(IN page bytea,
-    OUT lp smallint,
-    OUT lp_off smallint,
-    OUT lp_flags smallint,
-    OUT lp_len smallint,
-    OUT t_xmin xid,
-    OUT t_xmax xid,
-    OUT t_field3 int4,
-    OUT t_ctid tid,
-    OUT t_infomask2 integer,
-    OUT t_infomask integer,
-    OUT t_hoff smallint,
-    OUT t_bits text,
-    OUT t_oid oid)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'heap_page_items'
-LANGUAGE C STRICT;
-
---
--- bt_metap()
---
-CREATE FUNCTION bt_metap(IN relname text,
-    OUT magic int4,
-    OUT version int4,
-    OUT root int4,
-    OUT level int4,
-    OUT fastroot int4,
-    OUT fastlevel int4)
-AS 'MODULE_PATHNAME', 'bt_metap'
-LANGUAGE C STRICT;
-
---
--- bt_page_stats()
---
-CREATE FUNCTION bt_page_stats(IN relname text, IN blkno int4,
-    OUT blkno int4,
-    OUT type "char",
-    OUT live_items int4,
-    OUT dead_items int4,
-    OUT avg_item_size int4,
-    OUT page_size int4,
-    OUT free_size int4,
-    OUT btpo_prev int4,
-    OUT btpo_next int4,
-    OUT btpo int4,
-    OUT btpo_flags int4)
-AS 'MODULE_PATHNAME', 'bt_page_stats'
-LANGUAGE C STRICT;
-
---
--- bt_page_items()
---
-CREATE FUNCTION bt_page_items(IN relname text, IN blkno int4,
-    OUT itemoffset smallint,
-    OUT ctid tid,
-    OUT itemlen smallint,
-    OUT nulls bool,
-    OUT vars bool,
-    OUT data text)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'bt_page_items'
-LANGUAGE C STRICT;
-
---
--- fsm_page_contents()
---
-CREATE FUNCTION fsm_page_contents(IN page bytea)
-RETURNS text
-AS 'MODULE_PATHNAME', 'fsm_page_contents'
-LANGUAGE C STRICT;
diff --git a/contrib/pageinspect/pageinspect--unpackaged--1.0.sql b/contrib/pageinspect/pageinspect--unpackaged--1.0.sql
deleted file mode 100644
index 7d4feaf..0000000
--- a/contrib/pageinspect/pageinspect--unpackaged--1.0.sql
+++ /dev/null
@@ -1,28 +0,0 @@
-/* contrib/pageinspect/pageinspect--unpackaged--1.0.sql */
-
-DROP FUNCTION heap_page_items(bytea);
-CREATE FUNCTION heap_page_items(IN page bytea,
-	OUT lp smallint,
-	OUT lp_off smallint,
-	OUT lp_flags smallint,
-	OUT lp_len smallint,
-	OUT t_xmin xid,
-	OUT t_xmax xid,
-	OUT t_field3 int4,
-	OUT t_ctid tid,
-	OUT t_infomask2 integer,
-	OUT t_infomask integer,
-	OUT t_hoff smallint,
-	OUT t_bits text,
-	OUT t_oid oid)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'heap_page_items'
-LANGUAGE C STRICT;
-
-ALTER EXTENSION pageinspect ADD function get_raw_page(text,integer);
-ALTER EXTENSION pageinspect ADD function get_raw_page(text,text,integer);
-ALTER EXTENSION pageinspect ADD function page_header(bytea);
-ALTER EXTENSION pageinspect ADD function bt_metap(text);
-ALTER EXTENSION pageinspect ADD function bt_page_stats(text,integer);
-ALTER EXTENSION pageinspect ADD function bt_page_items(text,integer);
-ALTER EXTENSION pageinspect ADD function fsm_page_contents(bytea);
diff --git a/contrib/pageinspect/pageinspect.control b/contrib/pageinspect/pageinspect.control
deleted file mode 100644
index f9da0e8..0000000
--- a/contrib/pageinspect/pageinspect.control
+++ /dev/null
@@ -1,5 +0,0 @@
-# pageinspect extension
-comment = 'inspect the contents of database pages at a low level'
-default_version = '1.0'
-module_pathname = '$libdir/pageinspect'
-relocatable = true
diff --git a/contrib/pageinspect/rawpage.c b/contrib/pageinspect/rawpage.c
deleted file mode 100644
index 2607576..0000000
--- a/contrib/pageinspect/rawpage.c
+++ /dev/null
@@ -1,232 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * rawpage.c
- *	  Functions to extract a raw page as bytea and inspect it
- *
- * Access-method specific inspection functions are in separate files.
- *
- * Copyright (c) 2007-2011, PostgreSQL Global Development Group
- *
- * IDENTIFICATION
- *	  contrib/pageinspect/rawpage.c
- *
- *-------------------------------------------------------------------------
- */
-
-#include "postgres.h"
-
-#include "access/heapam.h"
-#include "access/transam.h"
-#include "catalog/catalog.h"
-#include "catalog/namespace.h"
-#include "catalog/pg_type.h"
-#include "fmgr.h"
-#include "funcapi.h"
-#include "miscadmin.h"
-#include "storage/bufmgr.h"
-#include "utils/builtins.h"
-
-PG_MODULE_MAGIC;
-
-Datum		get_raw_page(PG_FUNCTION_ARGS);
-Datum		get_raw_page_fork(PG_FUNCTION_ARGS);
-Datum		page_header(PG_FUNCTION_ARGS);
-
-static bytea *get_raw_page_internal(text *relname, ForkNumber forknum,
-					  BlockNumber blkno);
-
-
-/*
- * get_raw_page
- *
- * Returns a copy of a page from shared buffers as a bytea
- */
-PG_FUNCTION_INFO_V1(get_raw_page);
-
-Datum
-get_raw_page(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	uint32		blkno = PG_GETARG_UINT32(1);
-	bytea	   *raw_page;
-
-	/*
-	 * We don't normally bother to check the number of arguments to a C
-	 * function, but here it's needed for safety because early 8.4 beta
-	 * releases mistakenly redefined get_raw_page() as taking three arguments.
-	 */
-	if (PG_NARGS() != 2)
-		ereport(ERROR,
-				(errmsg("wrong number of arguments to get_raw_page()"),
-				 errhint("Run the updated pageinspect.sql script.")));
-
-	raw_page = get_raw_page_internal(relname, MAIN_FORKNUM, blkno);
-
-	PG_RETURN_BYTEA_P(raw_page);
-}
-
-/*
- * get_raw_page_fork
- *
- * Same, for any fork
- */
-PG_FUNCTION_INFO_V1(get_raw_page_fork);
-
-Datum
-get_raw_page_fork(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	text	   *forkname = PG_GETARG_TEXT_P(1);
-	uint32		blkno = PG_GETARG_UINT32(2);
-	bytea	   *raw_page;
-	ForkNumber	forknum;
-
-	forknum = forkname_to_number(text_to_cstring(forkname));
-
-	raw_page = get_raw_page_internal(relname, forknum, blkno);
-
-	PG_RETURN_BYTEA_P(raw_page);
-}
-
-/*
- * workhorse
- */
-static bytea *
-get_raw_page_internal(text *relname, ForkNumber forknum, BlockNumber blkno)
-{
-	bytea	   *raw_page;
-	RangeVar   *relrv;
-	Relation	rel;
-	char	   *raw_page_data;
-	Buffer		buf;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use raw functions"))));
-
-	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-	rel = relation_openrv(relrv, AccessShareLock);
-
-	/* Check that this relation has storage */
-	if (rel->rd_rel->relkind == RELKIND_VIEW)
-		ereport(ERROR,
-				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-				 errmsg("cannot get raw page from view \"%s\"",
-						RelationGetRelationName(rel))));
-	if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
-		ereport(ERROR,
-				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-				 errmsg("cannot get raw page from composite type \"%s\"",
-						RelationGetRelationName(rel))));
-	if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
-		ereport(ERROR,
-				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-				 errmsg("cannot get raw page from foreign table \"%s\"",
-						RelationGetRelationName(rel))));
-
-	/*
-	 * Reject attempts to read non-local temporary relations; we would be
-	 * likely to get wrong data since we have no visibility into the owning
-	 * session's local buffers.
-	 */
-	if (RELATION_IS_OTHER_TEMP(rel))
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot access temporary tables of other sessions")));
-
-	if (blkno >= RelationGetNumberOfBlocks(rel))
-		elog(ERROR, "block number %u is out of range for relation \"%s\"",
-			 blkno, RelationGetRelationName(rel));
-
-	/* Initialize buffer to copy to */
-	raw_page = (bytea *) palloc(BLCKSZ + VARHDRSZ);
-	SET_VARSIZE(raw_page, BLCKSZ + VARHDRSZ);
-	raw_page_data = VARDATA(raw_page);
-
-	/* Take a verbatim copy of the page */
-
-	buf = ReadBufferExtended(rel, forknum, blkno, RBM_NORMAL, NULL);
-	LockBuffer(buf, BUFFER_LOCK_SHARE);
-
-	memcpy(raw_page_data, BufferGetPage(buf), BLCKSZ);
-
-	LockBuffer(buf, BUFFER_LOCK_UNLOCK);
-	ReleaseBuffer(buf);
-
-	relation_close(rel, AccessShareLock);
-
-	return raw_page;
-}
-
-/*
- * page_header
- *
- * Allows inspection of page header fields of a raw page
- */
-
-PG_FUNCTION_INFO_V1(page_header);
-
-Datum
-page_header(PG_FUNCTION_ARGS)
-{
-	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
-	int			raw_page_size;
-
-	TupleDesc	tupdesc;
-
-	Datum		result;
-	HeapTuple	tuple;
-	Datum		values[9];
-	bool		nulls[9];
-
-	PageHeader	page;
-	XLogRecPtr	lsn;
-	char		lsnchar[64];
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use raw page functions"))));
-
-	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
-
-	/*
-	 * Check that enough data was supplied, so that we don't try to access
-	 * fields outside the supplied buffer.
-	 */
-	if (raw_page_size < sizeof(PageHeaderData))
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("input page too small (%d bytes)", raw_page_size)));
-
-	page = (PageHeader) VARDATA(raw_page);
-
-	/* Build a tuple descriptor for our result type */
-	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
-		elog(ERROR, "return type must be a row type");
-
-	/* Extract information from the page header */
-
-	lsn = PageGetLSN(page);
-	snprintf(lsnchar, sizeof(lsnchar), "%X/%X", lsn.xlogid, lsn.xrecoff);
-
-	values[0] = CStringGetTextDatum(lsnchar);
-	values[1] = UInt16GetDatum(PageGetTLI(page));
-	values[2] = UInt16GetDatum(page->pd_flags);
-	values[3] = UInt16GetDatum(page->pd_lower);
-	values[4] = UInt16GetDatum(page->pd_upper);
-	values[5] = UInt16GetDatum(page->pd_special);
-	values[6] = UInt16GetDatum(PageGetPageSize(page));
-	values[7] = UInt16GetDatum(PageGetPageLayoutVersion(page));
-	values[8] = TransactionIdGetDatum(page->pd_prune_xid);
-
-	/* Build and return the tuple. */
-
-	memset(nulls, 0, sizeof(nulls));
-
-	tuple = heap_form_tuple(tupdesc, values, nulls);
-	result = HeapTupleGetDatum(tuple);
-
-	PG_RETURN_DATUM(result);
-}
diff --git a/contrib/pg_buffercache/Makefile b/contrib/pg_buffercache/Makefile
deleted file mode 100644
index 323c0ac..0000000
--- a/contrib/pg_buffercache/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-# contrib/pg_buffercache/Makefile
-
-MODULE_big = pg_buffercache
-OBJS = pg_buffercache_pages.o
-
-EXTENSION = pg_buffercache
-DATA = pg_buffercache--1.0.sql pg_buffercache--unpackaged--1.0.sql
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/pg_buffercache
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
diff --git a/contrib/pg_buffercache/pg_buffercache--1.0.sql b/contrib/pg_buffercache/pg_buffercache--1.0.sql
deleted file mode 100644
index 9407d21..0000000
--- a/contrib/pg_buffercache/pg_buffercache--1.0.sql
+++ /dev/null
@@ -1,17 +0,0 @@
-/* contrib/pg_buffercache/pg_buffercache--1.0.sql */
-
--- Register the function.
-CREATE FUNCTION pg_buffercache_pages()
-RETURNS SETOF RECORD
-AS 'MODULE_PATHNAME', 'pg_buffercache_pages'
-LANGUAGE C;
-
--- Create a view for convenient access.
-CREATE VIEW pg_buffercache AS
-	SELECT P.* FROM pg_buffercache_pages() AS P
-	(bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,
-	 relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2);
-
--- Don't want these to be available to public.
-REVOKE ALL ON FUNCTION pg_buffercache_pages() FROM PUBLIC;
-REVOKE ALL ON pg_buffercache FROM PUBLIC;
diff --git a/contrib/pg_buffercache/pg_buffercache--unpackaged--1.0.sql b/contrib/pg_buffercache/pg_buffercache--unpackaged--1.0.sql
deleted file mode 100644
index f00a954..0000000
--- a/contrib/pg_buffercache/pg_buffercache--unpackaged--1.0.sql
+++ /dev/null
@@ -1,4 +0,0 @@
-/* contrib/pg_buffercache/pg_buffercache--unpackaged--1.0.sql */
-
-ALTER EXTENSION pg_buffercache ADD function pg_buffercache_pages();
-ALTER EXTENSION pg_buffercache ADD view pg_buffercache;
diff --git a/contrib/pg_buffercache/pg_buffercache.control b/contrib/pg_buffercache/pg_buffercache.control
deleted file mode 100644
index 709513c..0000000
--- a/contrib/pg_buffercache/pg_buffercache.control
+++ /dev/null
@@ -1,5 +0,0 @@
-# pg_buffercache extension
-comment = 'examine the shared buffer cache'
-default_version = '1.0'
-module_pathname = '$libdir/pg_buffercache'
-relocatable = true
diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c
deleted file mode 100644
index ed88288..0000000
--- a/contrib/pg_buffercache/pg_buffercache_pages.c
+++ /dev/null
@@ -1,219 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * pg_buffercache_pages.c
- *	  display some contents of the buffer cache
- *
- *	  contrib/pg_buffercache/pg_buffercache_pages.c
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include "access/heapam.h"
-#include "catalog/pg_type.h"
-#include "funcapi.h"
-#include "storage/buf_internals.h"
-#include "storage/bufmgr.h"
-#include "utils/relcache.h"
-
-
-#define NUM_BUFFERCACHE_PAGES_ELEM	8
-
-PG_MODULE_MAGIC;
-
-Datum		pg_buffercache_pages(PG_FUNCTION_ARGS);
-
-
-/*
- * Record structure holding the to be exposed cache data.
- */
-typedef struct
-{
-	uint32		bufferid;
-	Oid			relfilenode;
-	Oid			reltablespace;
-	Oid			reldatabase;
-	ForkNumber	forknum;
-	BlockNumber blocknum;
-	bool		isvalid;
-	bool		isdirty;
-	uint16		usagecount;
-} BufferCachePagesRec;
-
-
-/*
- * Function context for data persisting over repeated calls.
- */
-typedef struct
-{
-	TupleDesc	tupdesc;
-	BufferCachePagesRec *record;
-} BufferCachePagesContext;
-
-
-/*
- * Function returning data from the shared buffer cache - buffer number,
- * relation node/tablespace/database/blocknum and dirty indicator.
- */
-PG_FUNCTION_INFO_V1(pg_buffercache_pages);
-
-Datum
-pg_buffercache_pages(PG_FUNCTION_ARGS)
-{
-	FuncCallContext *funcctx;
-	Datum		result;
-	MemoryContext oldcontext;
-	BufferCachePagesContext *fctx;		/* User function context. */
-	TupleDesc	tupledesc;
-	HeapTuple	tuple;
-
-	if (SRF_IS_FIRSTCALL())
-	{
-		int			i;
-		volatile BufferDesc *bufHdr;
-
-		funcctx = SRF_FIRSTCALL_INIT();
-
-		/* Switch context when allocating stuff to be used in later calls */
-		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
-
-		/* Create a user function context for cross-call persistence */
-		fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
-
-		/* Construct a tuple descriptor for the result rows. */
-		tupledesc = CreateTemplateTupleDesc(NUM_BUFFERCACHE_PAGES_ELEM, false);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
-						   INT4OID, -1, 0);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 2, "relfilenode",
-						   OIDOID, -1, 0);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 3, "reltablespace",
-						   OIDOID, -1, 0);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 4, "reldatabase",
-						   OIDOID, -1, 0);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 5, "relforknumber",
-						   INT2OID, -1, 0);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 6, "relblocknumber",
-						   INT8OID, -1, 0);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 7, "isdirty",
-						   BOOLOID, -1, 0);
-		TupleDescInitEntry(tupledesc, (AttrNumber) 8, "usage_count",
-						   INT2OID, -1, 0);
-
-		fctx->tupdesc = BlessTupleDesc(tupledesc);
-
-		/* Allocate NBuffers worth of BufferCachePagesRec records. */
-		fctx->record = (BufferCachePagesRec *) palloc(sizeof(BufferCachePagesRec) * NBuffers);
-
-		/* Set max calls and remember the user function context. */
-		funcctx->max_calls = NBuffers;
-		funcctx->user_fctx = fctx;
-
-		/* Return to original context when allocating transient memory */
-		MemoryContextSwitchTo(oldcontext);
-
-		/*
-		 * To get a consistent picture of the buffer state, we must lock all
-		 * partitions of the buffer map.  Needless to say, this is horrible
-		 * for concurrency.  Must grab locks in increasing order to avoid
-		 * possible deadlocks.
-		 */
-		for (i = 0; i < NUM_BUFFER_PARTITIONS; i++)
-			LWLockAcquire(FirstBufMappingLock + i, LW_SHARED);
-
-		/*
-		 * Scan though all the buffers, saving the relevant fields in the
-		 * fctx->record structure.
-		 */
-		for (i = 0, bufHdr = BufferDescriptors; i < NBuffers; i++, bufHdr++)
-		{
-			/* Lock each buffer header before inspecting. */
-			LockBufHdr(bufHdr);
-
-			fctx->record[i].bufferid = BufferDescriptorGetBuffer(bufHdr);
-			fctx->record[i].relfilenode = bufHdr->tag.rnode.relNode;
-			fctx->record[i].reltablespace = bufHdr->tag.rnode.spcNode;
-			fctx->record[i].reldatabase = bufHdr->tag.rnode.dbNode;
-			fctx->record[i].forknum = bufHdr->tag.forkNum;
-			fctx->record[i].blocknum = bufHdr->tag.blockNum;
-			fctx->record[i].usagecount = bufHdr->usage_count;
-
-			if (bufHdr->flags & BM_DIRTY)
-				fctx->record[i].isdirty = true;
-			else
-				fctx->record[i].isdirty = false;
-
-			/* Note if the buffer is valid, and has storage created */
-			if ((bufHdr->flags & BM_VALID) && (bufHdr->flags & BM_TAG_VALID))
-				fctx->record[i].isvalid = true;
-			else
-				fctx->record[i].isvalid = false;
-
-			UnlockBufHdr(bufHdr);
-		}
-
-		/*
-		 * And release locks.  We do this in reverse order for two reasons:
-		 * (1) Anyone else who needs more than one of the locks will be trying
-		 * to lock them in increasing order; we don't want to release the
-		 * other process until it can get all the locks it needs. (2) This
-		 * avoids O(N^2) behavior inside LWLockRelease.
-		 */
-		for (i = NUM_BUFFER_PARTITIONS; --i >= 0;)
-			LWLockRelease(FirstBufMappingLock + i);
-	}
-
-	funcctx = SRF_PERCALL_SETUP();
-
-	/* Get the saved state */
-	fctx = funcctx->user_fctx;
-
-	if (funcctx->call_cntr < funcctx->max_calls)
-	{
-		uint32		i = funcctx->call_cntr;
-		Datum		values[NUM_BUFFERCACHE_PAGES_ELEM];
-		bool		nulls[NUM_BUFFERCACHE_PAGES_ELEM];
-
-		values[0] = Int32GetDatum(fctx->record[i].bufferid);
-		nulls[0] = false;
-
-		/*
-		 * Set all fields except the bufferid to null if the buffer is unused
-		 * or not valid.
-		 */
-		if (fctx->record[i].blocknum == InvalidBlockNumber ||
-			fctx->record[i].isvalid == false)
-		{
-			nulls[1] = true;
-			nulls[2] = true;
-			nulls[3] = true;
-			nulls[4] = true;
-			nulls[5] = true;
-			nulls[6] = true;
-			nulls[7] = true;
-		}
-		else
-		{
-			values[1] = ObjectIdGetDatum(fctx->record[i].relfilenode);
-			nulls[1] = false;
-			values[2] = ObjectIdGetDatum(fctx->record[i].reltablespace);
-			nulls[2] = false;
-			values[3] = ObjectIdGetDatum(fctx->record[i].reldatabase);
-			nulls[3] = false;
-			values[4] = ObjectIdGetDatum(fctx->record[i].forknum);
-			nulls[4] = false;
-			values[5] = Int64GetDatum((int64) fctx->record[i].blocknum);
-			nulls[5] = false;
-			values[6] = BoolGetDatum(fctx->record[i].isdirty);
-			nulls[6] = false;
-			values[7] = Int16GetDatum(fctx->record[i].usagecount);
-			nulls[7] = false;
-		}
-
-		/* Build and return the tuple. */
-		tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
-		result = HeapTupleGetDatum(tuple);
-
-		SRF_RETURN_NEXT(funcctx, result);
-	}
-	else
-		SRF_RETURN_DONE(funcctx);
-}
diff --git a/contrib/pg_freespacemap/Makefile b/contrib/pg_freespacemap/Makefile
deleted file mode 100644
index b2e3ba3..0000000
--- a/contrib/pg_freespacemap/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-# contrib/pg_freespacemap/Makefile
-
-MODULE_big = pg_freespacemap
-OBJS = pg_freespacemap.o
-
-EXTENSION = pg_freespacemap
-DATA = pg_freespacemap--1.0.sql pg_freespacemap--unpackaged--1.0.sql
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/pg_freespacemap
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
diff --git a/contrib/pg_freespacemap/pg_freespacemap--1.0.sql b/contrib/pg_freespacemap/pg_freespacemap--1.0.sql
deleted file mode 100644
index d63420e..0000000
--- a/contrib/pg_freespacemap/pg_freespacemap--1.0.sql
+++ /dev/null
@@ -1,22 +0,0 @@
-/* contrib/pg_freespacemap/pg_freespacemap--1.0.sql */
-
--- Register the C function.
-CREATE FUNCTION pg_freespace(regclass, bigint)
-RETURNS int2
-AS 'MODULE_PATHNAME', 'pg_freespace'
-LANGUAGE C STRICT;
-
--- pg_freespace shows the recorded space avail at each block in a relation
-CREATE FUNCTION
-  pg_freespace(rel regclass, blkno OUT bigint, avail OUT int2)
-RETURNS SETOF RECORD
-AS $$
-  SELECT blkno, pg_freespace($1, blkno) AS avail
-  FROM generate_series(0, pg_relation_size($1) / current_setting('block_size')::bigint - 1) AS blkno;
-$$
-LANGUAGE SQL;
-
-
--- Don't want these to be available to public.
-REVOKE ALL ON FUNCTION pg_freespace(regclass, bigint) FROM PUBLIC;
-REVOKE ALL ON FUNCTION pg_freespace(regclass) FROM PUBLIC;
diff --git a/contrib/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql b/contrib/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql
deleted file mode 100644
index 4c7487f..0000000
--- a/contrib/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql
+++ /dev/null
@@ -1,4 +0,0 @@
-/* contrib/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql */
-
-ALTER EXTENSION pg_freespacemap ADD function pg_freespace(regclass,bigint);
-ALTER EXTENSION pg_freespacemap ADD function pg_freespace(regclass);
diff --git a/contrib/pg_freespacemap/pg_freespacemap.c b/contrib/pg_freespacemap/pg_freespacemap.c
deleted file mode 100644
index bf6b0df..0000000
--- a/contrib/pg_freespacemap/pg_freespacemap.c
+++ /dev/null
@@ -1,46 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * pg_freespacemap.c
- *	  display contents of a free space map
- *
- *	  contrib/pg_freespacemap/pg_freespacemap.c
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include "access/heapam.h"
-#include "funcapi.h"
-#include "storage/block.h"
-#include "storage/freespace.h"
-
-
-PG_MODULE_MAGIC;
-
-Datum		pg_freespace(PG_FUNCTION_ARGS);
-
-/*
- * Returns the amount of free space on a given page, according to the
- * free space map.
- */
-PG_FUNCTION_INFO_V1(pg_freespace);
-
-Datum
-pg_freespace(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	int64		blkno = PG_GETARG_INT64(1);
-	int16		freespace;
-	Relation	rel;
-
-	rel = relation_open(relid, AccessShareLock);
-
-	if (blkno < 0 || blkno > MaxBlockNumber)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("invalid block number")));
-
-	freespace = GetRecordedFreeSpace(rel, blkno);
-
-	relation_close(rel, AccessShareLock);
-	PG_RETURN_INT16(freespace);
-}
diff --git a/contrib/pg_freespacemap/pg_freespacemap.control b/contrib/pg_freespacemap/pg_freespacemap.control
deleted file mode 100644
index 34b695f..0000000
--- a/contrib/pg_freespacemap/pg_freespacemap.control
+++ /dev/null
@@ -1,5 +0,0 @@
-# pg_freespacemap extension
-comment = 'examine the free space map (FSM)'
-default_version = '1.0'
-module_pathname = '$libdir/pg_freespacemap'
-relocatable = true
diff --git a/contrib/pg_stat_statements/Makefile b/contrib/pg_stat_statements/Makefile
deleted file mode 100644
index e086fd8..0000000
--- a/contrib/pg_stat_statements/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-# contrib/pg_stat_statements/Makefile
-
-MODULE_big = pg_stat_statements
-OBJS = pg_stat_statements.o
-
-EXTENSION = pg_stat_statements
-DATA = pg_stat_statements--1.0.sql pg_stat_statements--unpackaged--1.0.sql
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/pg_stat_statements
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.0.sql b/contrib/pg_stat_statements/pg_stat_statements--1.0.sql
deleted file mode 100644
index e17b82c..0000000
--- a/contrib/pg_stat_statements/pg_stat_statements--1.0.sql
+++ /dev/null
@@ -1,36 +0,0 @@
-/* contrib/pg_stat_statements/pg_stat_statements--1.0.sql */
-
--- Register functions.
-CREATE FUNCTION pg_stat_statements_reset()
-RETURNS void
-AS 'MODULE_PATHNAME'
-LANGUAGE C;
-
-CREATE FUNCTION pg_stat_statements(
-    OUT userid oid,
-    OUT dbid oid,
-    OUT query text,
-    OUT calls int8,
-    OUT total_time float8,
-    OUT rows int8,
-    OUT shared_blks_hit int8,
-    OUT shared_blks_read int8,
-    OUT shared_blks_written int8,
-    OUT local_blks_hit int8,
-    OUT local_blks_read int8,
-    OUT local_blks_written int8,
-    OUT temp_blks_read int8,
-    OUT temp_blks_written int8
-)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME'
-LANGUAGE C;
-
--- Register a view on the function for ease of use.
-CREATE VIEW pg_stat_statements AS
-  SELECT * FROM pg_stat_statements();
-
-GRANT SELECT ON pg_stat_statements TO PUBLIC;
-
--- Don't want this to be available to non-superusers.
-REVOKE ALL ON FUNCTION pg_stat_statements_reset() FROM PUBLIC;
diff --git a/contrib/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql b/contrib/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql
deleted file mode 100644
index 9dda85c..0000000
--- a/contrib/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql
+++ /dev/null
@@ -1,5 +0,0 @@
-/* contrib/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql */
-
-ALTER EXTENSION pg_stat_statements ADD function pg_stat_statements_reset();
-ALTER EXTENSION pg_stat_statements ADD function pg_stat_statements();
-ALTER EXTENSION pg_stat_statements ADD view pg_stat_statements;
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
deleted file mode 100644
index 0236b87..0000000
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ /dev/null
@@ -1,1046 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * pg_stat_statements.c
- *		Track statement execution times across a whole database cluster.
- *
- * Note about locking issues: to create or delete an entry in the shared
- * hashtable, one must hold pgss->lock exclusively.  Modifying any field
- * in an entry except the counters requires the same.  To look up an entry,
- * one must hold the lock shared.  To read or update the counters within
- * an entry, one must hold the lock shared or exclusive (so the entry doesn't
- * disappear!) and also take the entry's mutex spinlock.
- *
- *
- * Copyright (c) 2008-2011, PostgreSQL Global Development Group
- *
- * IDENTIFICATION
- *	  contrib/pg_stat_statements/pg_stat_statements.c
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include <unistd.h>
-
-#include "access/hash.h"
-#include "catalog/pg_type.h"
-#include "executor/executor.h"
-#include "executor/instrument.h"
-#include "funcapi.h"
-#include "mb/pg_wchar.h"
-#include "miscadmin.h"
-#include "pgstat.h"
-#include "storage/fd.h"
-#include "storage/ipc.h"
-#include "storage/spin.h"
-#include "tcop/utility.h"
-#include "utils/builtins.h"
-#include "utils/hsearch.h"
-#include "utils/guc.h"
-
-
-PG_MODULE_MAGIC;
-
-/* Location of stats file */
-#define PGSS_DUMP_FILE	"global/pg_stat_statements.stat"
-
-/* This constant defines the magic number in the stats file header */
-static const uint32 PGSS_FILE_HEADER = 0x20100108;
-
-/* XXX: Should USAGE_EXEC reflect execution time and/or buffer usage? */
-#define USAGE_EXEC(duration)	(1.0)
-#define USAGE_INIT				(1.0)	/* including initial planning */
-#define USAGE_DECREASE_FACTOR	(0.99)	/* decreased every entry_dealloc */
-#define USAGE_DEALLOC_PERCENT	5		/* free this % of entries at once */
-
-/*
- * Hashtable key that defines the identity of a hashtable entry.  The
- * hash comparators do not assume that the query string is null-terminated;
- * this lets us search for an mbcliplen'd string without copying it first.
- *
- * Presently, the query encoding is fully determined by the source database
- * and so we don't really need it to be in the key.  But that might not always
- * be true. Anyway it's notationally convenient to pass it as part of the key.
- */
-typedef struct pgssHashKey
-{
-	Oid			userid;			/* user OID */
-	Oid			dbid;			/* database OID */
-	int			encoding;		/* query encoding */
-	int			query_len;		/* # of valid bytes in query string */
-	const char *query_ptr;		/* query string proper */
-} pgssHashKey;
-
-/*
- * The actual stats counters kept within pgssEntry.
- */
-typedef struct Counters
-{
-	int64		calls;			/* # of times executed */
-	double		total_time;		/* total execution time in seconds */
-	int64		rows;			/* total # of retrieved or affected rows */
-	int64		shared_blks_hit;	/* # of shared buffer hits */
-	int64		shared_blks_read;		/* # of shared disk blocks read */
-	int64		shared_blks_written;	/* # of shared disk blocks written */
-	int64		local_blks_hit; /* # of local buffer hits */
-	int64		local_blks_read;	/* # of local disk blocks read */
-	int64		local_blks_written;		/* # of local disk blocks written */
-	int64		temp_blks_read; /* # of temp blocks read */
-	int64		temp_blks_written;		/* # of temp blocks written */
-	double		usage;			/* usage factor */
-} Counters;
-
-/*
- * Statistics per statement
- *
- * NB: see the file read/write code before changing field order here.
- */
-typedef struct pgssEntry
-{
-	pgssHashKey key;			/* hash key of entry - MUST BE FIRST */
-	Counters	counters;		/* the statistics for this query */
-	slock_t		mutex;			/* protects the counters only */
-	char		query[1];		/* VARIABLE LENGTH ARRAY - MUST BE LAST */
-	/* Note: the allocated length of query[] is actually pgss->query_size */
-} pgssEntry;
-
-/*
- * Global shared state
- */
-typedef struct pgssSharedState
-{
-	LWLockId	lock;			/* protects hashtable search/modification */
-	int			query_size;		/* max query length in bytes */
-} pgssSharedState;
-
-/*---- Local variables ----*/
-
-/* Current nesting depth of ExecutorRun calls */
-static int	nested_level = 0;
-
-/* Saved hook values in case of unload */
-static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
-static ExecutorStart_hook_type prev_ExecutorStart = NULL;
-static ExecutorRun_hook_type prev_ExecutorRun = NULL;
-static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
-static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
-static ProcessUtility_hook_type prev_ProcessUtility = NULL;
-
-/* Links to shared memory state */
-static pgssSharedState *pgss = NULL;
-static HTAB *pgss_hash = NULL;
-
-/*---- GUC variables ----*/
-
-typedef enum
-{
-	PGSS_TRACK_NONE,			/* track no statements */
-	PGSS_TRACK_TOP,				/* only top level statements */
-	PGSS_TRACK_ALL				/* all statements, including nested ones */
-}	PGSSTrackLevel;
-
-static const struct config_enum_entry track_options[] =
-{
-	{"none", PGSS_TRACK_NONE, false},
-	{"top", PGSS_TRACK_TOP, false},
-	{"all", PGSS_TRACK_ALL, false},
-	{NULL, 0, false}
-};
-
-static int	pgss_max;			/* max # statements to track */
-static int	pgss_track;			/* tracking level */
-static bool pgss_track_utility; /* whether to track utility commands */
-static bool pgss_save;			/* whether to save stats across shutdown */
-
-
-#define pgss_enabled() \
-	(pgss_track == PGSS_TRACK_ALL || \
-	(pgss_track == PGSS_TRACK_TOP && nested_level == 0))
-
-/*---- Function declarations ----*/
-
-void		_PG_init(void);
-void		_PG_fini(void);
-
-Datum		pg_stat_statements_reset(PG_FUNCTION_ARGS);
-Datum		pg_stat_statements(PG_FUNCTION_ARGS);
-
-PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
-PG_FUNCTION_INFO_V1(pg_stat_statements);
-
-static void pgss_shmem_startup(void);
-static void pgss_shmem_shutdown(int code, Datum arg);
-static void pgss_ExecutorStart(QueryDesc *queryDesc, int eflags);
-static void pgss_ExecutorRun(QueryDesc *queryDesc,
-				 ScanDirection direction,
-				 long count);
-static void pgss_ExecutorFinish(QueryDesc *queryDesc);
-static void pgss_ExecutorEnd(QueryDesc *queryDesc);
-static void pgss_ProcessUtility(Node *parsetree,
-			  const char *queryString, ParamListInfo params, bool isTopLevel,
-					DestReceiver *dest, char *completionTag);
-static uint32 pgss_hash_fn(const void *key, Size keysize);
-static int	pgss_match_fn(const void *key1, const void *key2, Size keysize);
-static void pgss_store(const char *query, double total_time, uint64 rows,
-		   const BufferUsage *bufusage);
-static Size pgss_memsize(void);
-static pgssEntry *entry_alloc(pgssHashKey *key);
-static void entry_dealloc(void);
-static void entry_reset(void);
-
-
-/*
- * Module load callback
- */
-void
-_PG_init(void)
-{
-	/*
-	 * In order to create our shared memory area, we have to be loaded via
-	 * shared_preload_libraries.  If not, fall out without hooking into any of
-	 * the main system.  (We don't throw error here because it seems useful to
-	 * allow the pg_stat_statements functions to be created even when the
-	 * module isn't active.  The functions must protect themselves against
-	 * being called then, however.)
-	 */
-	if (!process_shared_preload_libraries_in_progress)
-		return;
-
-	/*
-	 * Define (or redefine) custom GUC variables.
-	 */
-	DefineCustomIntVariable("pg_stat_statements.max",
-	  "Sets the maximum number of statements tracked by pg_stat_statements.",
-							NULL,
-							&pgss_max,
-							1000,
-							100,
-							INT_MAX,
-							PGC_POSTMASTER,
-							0,
-							NULL,
-							NULL,
-							NULL);
-
-	DefineCustomEnumVariable("pg_stat_statements.track",
-			   "Selects which statements are tracked by pg_stat_statements.",
-							 NULL,
-							 &pgss_track,
-							 PGSS_TRACK_TOP,
-							 track_options,
-							 PGC_SUSET,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	DefineCustomBoolVariable("pg_stat_statements.track_utility",
-	   "Selects whether utility commands are tracked by pg_stat_statements.",
-							 NULL,
-							 &pgss_track_utility,
-							 true,
-							 PGC_SUSET,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	DefineCustomBoolVariable("pg_stat_statements.save",
-			   "Save pg_stat_statements statistics across server shutdowns.",
-							 NULL,
-							 &pgss_save,
-							 true,
-							 PGC_SIGHUP,
-							 0,
-							 NULL,
-							 NULL,
-							 NULL);
-
-	EmitWarningsOnPlaceholders("pg_stat_statements");
-
-	/*
-	 * Request additional shared resources.  (These are no-ops if we're not in
-	 * the postmaster process.)  We'll allocate or attach to the shared
-	 * resources in pgss_shmem_startup().
-	 */
-	RequestAddinShmemSpace(pgss_memsize());
-	RequestAddinLWLocks(1);
-
-	/*
-	 * Install hooks.
-	 */
-	prev_shmem_startup_hook = shmem_startup_hook;
-	shmem_startup_hook = pgss_shmem_startup;
-	prev_ExecutorStart = ExecutorStart_hook;
-	ExecutorStart_hook = pgss_ExecutorStart;
-	prev_ExecutorRun = ExecutorRun_hook;
-	ExecutorRun_hook = pgss_ExecutorRun;
-	prev_ExecutorFinish = ExecutorFinish_hook;
-	ExecutorFinish_hook = pgss_ExecutorFinish;
-	prev_ExecutorEnd = ExecutorEnd_hook;
-	ExecutorEnd_hook = pgss_ExecutorEnd;
-	prev_ProcessUtility = ProcessUtility_hook;
-	ProcessUtility_hook = pgss_ProcessUtility;
-}
-
-/*
- * Module unload callback
- */
-void
-_PG_fini(void)
-{
-	/* Uninstall hooks. */
-	shmem_startup_hook = prev_shmem_startup_hook;
-	ExecutorStart_hook = prev_ExecutorStart;
-	ExecutorRun_hook = prev_ExecutorRun;
-	ExecutorFinish_hook = prev_ExecutorFinish;
-	ExecutorEnd_hook = prev_ExecutorEnd;
-	ProcessUtility_hook = prev_ProcessUtility;
-}
-
-/*
- * shmem_startup hook: allocate or attach to shared memory,
- * then load any pre-existing statistics from file.
- */
-static void
-pgss_shmem_startup(void)
-{
-	bool		found;
-	HASHCTL		info;
-	FILE	   *file;
-	uint32		header;
-	int32		num;
-	int32		i;
-	int			query_size;
-	int			buffer_size;
-	char	   *buffer = NULL;
-
-	if (prev_shmem_startup_hook)
-		prev_shmem_startup_hook();
-
-	/* reset in case this is a restart within the postmaster */
-	pgss = NULL;
-	pgss_hash = NULL;
-
-	/*
-	 * Create or attach to the shared memory state, including hash table
-	 */
-	LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
-
-	pgss = ShmemInitStruct("pg_stat_statements",
-						   sizeof(pgssSharedState),
-						   &found);
-
-	if (!found)
-	{
-		/* First time through ... */
-		pgss->lock = LWLockAssign();
-		pgss->query_size = pgstat_track_activity_query_size;
-	}
-
-	/* Be sure everyone agrees on the hash table entry size */
-	query_size = pgss->query_size;
-
-	memset(&info, 0, sizeof(info));
-	info.keysize = sizeof(pgssHashKey);
-	info.entrysize = offsetof(pgssEntry, query) +query_size;
-	info.hash = pgss_hash_fn;
-	info.match = pgss_match_fn;
-	pgss_hash = ShmemInitHash("pg_stat_statements hash",
-							  pgss_max, pgss_max,
-							  &info,
-							  HASH_ELEM | HASH_FUNCTION | HASH_COMPARE);
-
-	LWLockRelease(AddinShmemInitLock);
-
-	/*
-	 * If we're in the postmaster (or a standalone backend...), set up a shmem
-	 * exit hook to dump the statistics to disk.
-	 */
-	if (!IsUnderPostmaster)
-		on_shmem_exit(pgss_shmem_shutdown, (Datum) 0);
-
-	/*
-	 * Attempt to load old statistics from the dump file, if this is the first
-	 * time through and we weren't told not to.
-	 */
-	if (found || !pgss_save)
-		return;
-
-	/*
-	 * Note: we don't bother with locks here, because there should be no other
-	 * processes running when this code is reached.
-	 */
-	file = AllocateFile(PGSS_DUMP_FILE, PG_BINARY_R);
-	if (file == NULL)
-	{
-		if (errno == ENOENT)
-			return;				/* ignore not-found error */
-		goto error;
-	}
-
-	buffer_size = query_size;
-	buffer = (char *) palloc(buffer_size);
-
-	if (fread(&header, sizeof(uint32), 1, file) != 1 ||
-		header != PGSS_FILE_HEADER ||
-		fread(&num, sizeof(int32), 1, file) != 1)
-		goto error;
-
-	for (i = 0; i < num; i++)
-	{
-		pgssEntry	temp;
-		pgssEntry  *entry;
-
-		if (fread(&temp, offsetof(pgssEntry, mutex), 1, file) != 1)
-			goto error;
-
-		/* Encoding is the only field we can easily sanity-check */
-		if (!PG_VALID_BE_ENCODING(temp.key.encoding))
-			goto error;
-
-		/* Previous incarnation might have had a larger query_size */
-		if (temp.key.query_len >= buffer_size)
-		{
-			buffer = (char *) repalloc(buffer, temp.key.query_len + 1);
-			buffer_size = temp.key.query_len + 1;
-		}
-
-		if (fread(buffer, 1, temp.key.query_len, file) != temp.key.query_len)
-			goto error;
-		buffer[temp.key.query_len] = '\0';
-
-		/* Clip to available length if needed */
-		if (temp.key.query_len >= query_size)
-			temp.key.query_len = pg_encoding_mbcliplen(temp.key.encoding,
-													   buffer,
-													   temp.key.query_len,
-													   query_size - 1);
-		temp.key.query_ptr = buffer;
-
-		/* make the hashtable entry (discards old entries if too many) */
-		entry = entry_alloc(&temp.key);
-
-		/* copy in the actual stats */
-		entry->counters = temp.counters;
-	}
-
-	pfree(buffer);
-	FreeFile(file);
-	return;
-
-error:
-	ereport(LOG,
-			(errcode_for_file_access(),
-			 errmsg("could not read pg_stat_statement file \"%s\": %m",
-					PGSS_DUMP_FILE)));
-	if (buffer)
-		pfree(buffer);
-	if (file)
-		FreeFile(file);
-	/* If possible, throw away the bogus file; ignore any error */
-	unlink(PGSS_DUMP_FILE);
-}
-
-/*
- * shmem_shutdown hook: Dump statistics into file.
- *
- * Note: we don't bother with acquiring lock, because there should be no
- * other processes running when this is called.
- */
-static void
-pgss_shmem_shutdown(int code, Datum arg)
-{
-	FILE	   *file;
-	HASH_SEQ_STATUS hash_seq;
-	int32		num_entries;
-	pgssEntry  *entry;
-
-	/* Don't try to dump during a crash. */
-	if (code)
-		return;
-
-	/* Safety check ... shouldn't get here unless shmem is set up. */
-	if (!pgss || !pgss_hash)
-		return;
-
-	/* Don't dump if told not to. */
-	if (!pgss_save)
-		return;
-
-	file = AllocateFile(PGSS_DUMP_FILE, PG_BINARY_W);
-	if (file == NULL)
-		goto error;
-
-	if (fwrite(&PGSS_FILE_HEADER, sizeof(uint32), 1, file) != 1)
-		goto error;
-	num_entries = hash_get_num_entries(pgss_hash);
-	if (fwrite(&num_entries, sizeof(int32), 1, file) != 1)
-		goto error;
-
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
-	{
-		int			len = entry->key.query_len;
-
-		if (fwrite(entry, offsetof(pgssEntry, mutex), 1, file) != 1 ||
-			fwrite(entry->query, 1, len, file) != len)
-			goto error;
-	}
-
-	if (FreeFile(file))
-	{
-		file = NULL;
-		goto error;
-	}
-
-	return;
-
-error:
-	ereport(LOG,
-			(errcode_for_file_access(),
-			 errmsg("could not write pg_stat_statement file \"%s\": %m",
-					PGSS_DUMP_FILE)));
-	if (file)
-		FreeFile(file);
-	unlink(PGSS_DUMP_FILE);
-}
-
-/*
- * ExecutorStart hook: start up tracking if needed
- */
-static void
-pgss_ExecutorStart(QueryDesc *queryDesc, int eflags)
-{
-	if (prev_ExecutorStart)
-		prev_ExecutorStart(queryDesc, eflags);
-	else
-		standard_ExecutorStart(queryDesc, eflags);
-
-	if (pgss_enabled())
-	{
-		/*
-		 * Set up to track total elapsed time in ExecutorRun.  Make sure the
-		 * space is allocated in the per-query context so it will go away at
-		 * ExecutorEnd.
-		 */
-		if (queryDesc->totaltime == NULL)
-		{
-			MemoryContext oldcxt;
-
-			oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
-			queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL);
-			MemoryContextSwitchTo(oldcxt);
-		}
-	}
-}
-
-/*
- * ExecutorRun hook: all we need do is track nesting depth
- */
-static void
-pgss_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count)
-{
-	nested_level++;
-	PG_TRY();
-	{
-		if (prev_ExecutorRun)
-			prev_ExecutorRun(queryDesc, direction, count);
-		else
-			standard_ExecutorRun(queryDesc, direction, count);
-		nested_level--;
-	}
-	PG_CATCH();
-	{
-		nested_level--;
-		PG_RE_THROW();
-	}
-	PG_END_TRY();
-}
-
-/*
- * ExecutorFinish hook: all we need do is track nesting depth
- */
-static void
-pgss_ExecutorFinish(QueryDesc *queryDesc)
-{
-	nested_level++;
-	PG_TRY();
-	{
-		if (prev_ExecutorFinish)
-			prev_ExecutorFinish(queryDesc);
-		else
-			standard_ExecutorFinish(queryDesc);
-		nested_level--;
-	}
-	PG_CATCH();
-	{
-		nested_level--;
-		PG_RE_THROW();
-	}
-	PG_END_TRY();
-}
-
-/*
- * ExecutorEnd hook: store results if needed
- */
-static void
-pgss_ExecutorEnd(QueryDesc *queryDesc)
-{
-	if (queryDesc->totaltime && pgss_enabled())
-	{
-		/*
-		 * Make sure stats accumulation is done.  (Note: it's okay if several
-		 * levels of hook all do this.)
-		 */
-		InstrEndLoop(queryDesc->totaltime);
-
-		pgss_store(queryDesc->sourceText,
-				   queryDesc->totaltime->total,
-				   queryDesc->estate->es_processed,
-				   &queryDesc->totaltime->bufusage);
-	}
-
-	if (prev_ExecutorEnd)
-		prev_ExecutorEnd(queryDesc);
-	else
-		standard_ExecutorEnd(queryDesc);
-}
-
-/*
- * ProcessUtility hook
- */
-static void
-pgss_ProcessUtility(Node *parsetree, const char *queryString,
-					ParamListInfo params, bool isTopLevel,
-					DestReceiver *dest, char *completionTag)
-{
-	if (pgss_track_utility && pgss_enabled())
-	{
-		instr_time	start;
-		instr_time	duration;
-		uint64		rows = 0;
-		BufferUsage bufusage;
-
-		bufusage = pgBufferUsage;
-		INSTR_TIME_SET_CURRENT(start);
-
-		nested_level++;
-		PG_TRY();
-		{
-			if (prev_ProcessUtility)
-				prev_ProcessUtility(parsetree, queryString, params,
-									isTopLevel, dest, completionTag);
-			else
-				standard_ProcessUtility(parsetree, queryString, params,
-										isTopLevel, dest, completionTag);
-			nested_level--;
-		}
-		PG_CATCH();
-		{
-			nested_level--;
-			PG_RE_THROW();
-		}
-		PG_END_TRY();
-
-		INSTR_TIME_SET_CURRENT(duration);
-		INSTR_TIME_SUBTRACT(duration, start);
-
-		/* parse command tag to retrieve the number of affected rows. */
-		if (completionTag &&
-			sscanf(completionTag, "COPY " UINT64_FORMAT, &rows) != 1)
-			rows = 0;
-
-		/* calc differences of buffer counters. */
-		bufusage.shared_blks_hit =
-			pgBufferUsage.shared_blks_hit - bufusage.shared_blks_hit;
-		bufusage.shared_blks_read =
-			pgBufferUsage.shared_blks_read - bufusage.shared_blks_read;
-		bufusage.shared_blks_written =
-			pgBufferUsage.shared_blks_written - bufusage.shared_blks_written;
-		bufusage.local_blks_hit =
-			pgBufferUsage.local_blks_hit - bufusage.local_blks_hit;
-		bufusage.local_blks_read =
-			pgBufferUsage.local_blks_read - bufusage.local_blks_read;
-		bufusage.local_blks_written =
-			pgBufferUsage.local_blks_written - bufusage.local_blks_written;
-		bufusage.temp_blks_read =
-			pgBufferUsage.temp_blks_read - bufusage.temp_blks_read;
-		bufusage.temp_blks_written =
-			pgBufferUsage.temp_blks_written - bufusage.temp_blks_written;
-
-		pgss_store(queryString, INSTR_TIME_GET_DOUBLE(duration), rows,
-				   &bufusage);
-	}
-	else
-	{
-		if (prev_ProcessUtility)
-			prev_ProcessUtility(parsetree, queryString, params,
-								isTopLevel, dest, completionTag);
-		else
-			standard_ProcessUtility(parsetree, queryString, params,
-									isTopLevel, dest, completionTag);
-	}
-}
-
-/*
- * Calculate hash value for a key
- */
-static uint32
-pgss_hash_fn(const void *key, Size keysize)
-{
-	const pgssHashKey *k = (const pgssHashKey *) key;
-
-	/* we don't bother to include encoding in the hash */
-	return hash_uint32((uint32) k->userid) ^
-		hash_uint32((uint32) k->dbid) ^
-		DatumGetUInt32(hash_any((const unsigned char *) k->query_ptr,
-								k->query_len));
-}
-
-/*
- * Compare two keys - zero means match
- */
-static int
-pgss_match_fn(const void *key1, const void *key2, Size keysize)
-{
-	const pgssHashKey *k1 = (const pgssHashKey *) key1;
-	const pgssHashKey *k2 = (const pgssHashKey *) key2;
-
-	if (k1->userid == k2->userid &&
-		k1->dbid == k2->dbid &&
-		k1->encoding == k2->encoding &&
-		k1->query_len == k2->query_len &&
-		memcmp(k1->query_ptr, k2->query_ptr, k1->query_len) == 0)
-		return 0;
-	else
-		return 1;
-}
-
-/*
- * Store some statistics for a statement.
- */
-static void
-pgss_store(const char *query, double total_time, uint64 rows,
-		   const BufferUsage *bufusage)
-{
-	pgssHashKey key;
-	double		usage;
-	pgssEntry  *entry;
-
-	Assert(query != NULL);
-
-	/* Safety check... */
-	if (!pgss || !pgss_hash)
-		return;
-
-	/* Set up key for hashtable search */
-	key.userid = GetUserId();
-	key.dbid = MyDatabaseId;
-	key.encoding = GetDatabaseEncoding();
-	key.query_len = strlen(query);
-	if (key.query_len >= pgss->query_size)
-		key.query_len = pg_encoding_mbcliplen(key.encoding,
-											  query,
-											  key.query_len,
-											  pgss->query_size - 1);
-	key.query_ptr = query;
-
-	usage = USAGE_EXEC(duration);
-
-	/* Lookup the hash table entry with shared lock. */
-	LWLockAcquire(pgss->lock, LW_SHARED);
-
-	entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
-	if (!entry)
-	{
-		/* Must acquire exclusive lock to add a new entry. */
-		LWLockRelease(pgss->lock);
-		LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
-		entry = entry_alloc(&key);
-	}
-
-	/* Grab the spinlock while updating the counters. */
-	{
-		volatile pgssEntry *e = (volatile pgssEntry *) entry;
-
-		SpinLockAcquire(&e->mutex);
-		e->counters.calls += 1;
-		e->counters.total_time += total_time;
-		e->counters.rows += rows;
-		e->counters.shared_blks_hit += bufusage->shared_blks_hit;
-		e->counters.shared_blks_read += bufusage->shared_blks_read;
-		e->counters.shared_blks_written += bufusage->shared_blks_written;
-		e->counters.local_blks_hit += bufusage->local_blks_hit;
-		e->counters.local_blks_read += bufusage->local_blks_read;
-		e->counters.local_blks_written += bufusage->local_blks_written;
-		e->counters.temp_blks_read += bufusage->temp_blks_read;
-		e->counters.temp_blks_written += bufusage->temp_blks_written;
-		e->counters.usage += usage;
-		SpinLockRelease(&e->mutex);
-	}
-
-	LWLockRelease(pgss->lock);
-}
-
-/*
- * Reset all statement statistics.
- */
-Datum
-pg_stat_statements_reset(PG_FUNCTION_ARGS)
-{
-	if (!pgss || !pgss_hash)
-		ereport(ERROR,
-				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-				 errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
-	entry_reset();
-	PG_RETURN_VOID();
-}
-
-#define PG_STAT_STATEMENTS_COLS		14
-
-/*
- * Retrieve statement statistics.
- */
-Datum
-pg_stat_statements(PG_FUNCTION_ARGS)
-{
-	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
-	TupleDesc	tupdesc;
-	Tuplestorestate *tupstore;
-	MemoryContext per_query_ctx;
-	MemoryContext oldcontext;
-	Oid			userid = GetUserId();
-	bool		is_superuser = superuser();
-	HASH_SEQ_STATUS hash_seq;
-	pgssEntry  *entry;
-
-	if (!pgss || !pgss_hash)
-		ereport(ERROR,
-				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-				 errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
-
-	/* check to see if caller supports us returning a tuplestore */
-	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("set-valued function called in context that cannot accept a set")));
-	if (!(rsinfo->allowedModes & SFRM_Materialize))
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("materialize mode required, but it is not " \
-						"allowed in this context")));
-
-	/* Build a tuple descriptor for our result type */
-	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
-		elog(ERROR, "return type must be a row type");
-
-	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
-	oldcontext = MemoryContextSwitchTo(per_query_ctx);
-
-	tupstore = tuplestore_begin_heap(true, false, work_mem);
-	rsinfo->returnMode = SFRM_Materialize;
-	rsinfo->setResult = tupstore;
-	rsinfo->setDesc = tupdesc;
-
-	MemoryContextSwitchTo(oldcontext);
-
-	LWLockAcquire(pgss->lock, LW_SHARED);
-
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
-	{
-		Datum		values[PG_STAT_STATEMENTS_COLS];
-		bool		nulls[PG_STAT_STATEMENTS_COLS];
-		int			i = 0;
-		Counters	tmp;
-
-		memset(values, 0, sizeof(values));
-		memset(nulls, 0, sizeof(nulls));
-
-		values[i++] = ObjectIdGetDatum(entry->key.userid);
-		values[i++] = ObjectIdGetDatum(entry->key.dbid);
-
-		if (is_superuser || entry->key.userid == userid)
-		{
-			char	   *qstr;
-
-			qstr = (char *)
-				pg_do_encoding_conversion((unsigned char *) entry->query,
-										  entry->key.query_len,
-										  entry->key.encoding,
-										  GetDatabaseEncoding());
-			values[i++] = CStringGetTextDatum(qstr);
-			if (qstr != entry->query)
-				pfree(qstr);
-		}
-		else
-			values[i++] = CStringGetTextDatum("<insufficient privilege>");
-
-		/* copy counters to a local variable to keep locking time short */
-		{
-			volatile pgssEntry *e = (volatile pgssEntry *) entry;
-
-			SpinLockAcquire(&e->mutex);
-			tmp = e->counters;
-			SpinLockRelease(&e->mutex);
-		}
-
-		values[i++] = Int64GetDatumFast(tmp.calls);
-		values[i++] = Float8GetDatumFast(tmp.total_time);
-		values[i++] = Int64GetDatumFast(tmp.rows);
-		values[i++] = Int64GetDatumFast(tmp.shared_blks_hit);
-		values[i++] = Int64GetDatumFast(tmp.shared_blks_read);
-		values[i++] = Int64GetDatumFast(tmp.shared_blks_written);
-		values[i++] = Int64GetDatumFast(tmp.local_blks_hit);
-		values[i++] = Int64GetDatumFast(tmp.local_blks_read);
-		values[i++] = Int64GetDatumFast(tmp.local_blks_written);
-		values[i++] = Int64GetDatumFast(tmp.temp_blks_read);
-		values[i++] = Int64GetDatumFast(tmp.temp_blks_written);
-
-		Assert(i == PG_STAT_STATEMENTS_COLS);
-
-		tuplestore_putvalues(tupstore, tupdesc, values, nulls);
-	}
-
-	LWLockRelease(pgss->lock);
-
-	/* clean up and return the tuplestore */
-	tuplestore_donestoring(tupstore);
-
-	return (Datum) 0;
-}
-
-/*
- * Estimate shared memory space needed.
- */
-static Size
-pgss_memsize(void)
-{
-	Size		size;
-	Size		entrysize;
-
-	size = MAXALIGN(sizeof(pgssSharedState));
-	entrysize = offsetof(pgssEntry, query) +pgstat_track_activity_query_size;
-	size = add_size(size, hash_estimate_size(pgss_max, entrysize));
-
-	return size;
-}
-
-/*
- * Allocate a new hashtable entry.
- * caller must hold an exclusive lock on pgss->lock
- *
- * Note: despite needing exclusive lock, it's not an error for the target
- * entry to already exist.	This is because pgss_store releases and
- * reacquires lock after failing to find a match; so someone else could
- * have made the entry while we waited to get exclusive lock.
- */
-static pgssEntry *
-entry_alloc(pgssHashKey *key)
-{
-	pgssEntry  *entry;
-	bool		found;
-
-	/* Caller must have clipped query properly */
-	Assert(key->query_len < pgss->query_size);
-
-	/* Make space if needed */
-	while (hash_get_num_entries(pgss_hash) >= pgss_max)
-		entry_dealloc();
-
-	/* Find or create an entry with desired hash code */
-	entry = (pgssEntry *) hash_search(pgss_hash, key, HASH_ENTER, &found);
-
-	if (!found)
-	{
-		/* New entry, initialize it */
-
-		/* dynahash tried to copy the key for us, but must fix query_ptr */
-		entry->key.query_ptr = entry->query;
-		/* reset the statistics */
-		memset(&entry->counters, 0, sizeof(Counters));
-		entry->counters.usage = USAGE_INIT;
-		/* re-initialize the mutex each time ... we assume no one using it */
-		SpinLockInit(&entry->mutex);
-		/* ... and don't forget the query text */
-		memcpy(entry->query, key->query_ptr, key->query_len);
-		entry->query[key->query_len] = '\0';
-	}
-
-	return entry;
-}
-
-/*
- * qsort comparator for sorting into increasing usage order
- */
-static int
-entry_cmp(const void *lhs, const void *rhs)
-{
-	double		l_usage = (*(const pgssEntry **) lhs)->counters.usage;
-	double		r_usage = (*(const pgssEntry **) rhs)->counters.usage;
-
-	if (l_usage < r_usage)
-		return -1;
-	else if (l_usage > r_usage)
-		return +1;
-	else
-		return 0;
-}
-
-/*
- * Deallocate least used entries.
- * Caller must hold an exclusive lock on pgss->lock.
- */
-static void
-entry_dealloc(void)
-{
-	HASH_SEQ_STATUS hash_seq;
-	pgssEntry **entries;
-	pgssEntry  *entry;
-	int			nvictims;
-	int			i;
-
-	/* Sort entries by usage and deallocate USAGE_DEALLOC_PERCENT of them. */
-
-	entries = palloc(hash_get_num_entries(pgss_hash) * sizeof(pgssEntry *));
-
-	i = 0;
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
-	{
-		entries[i++] = entry;
-		entry->counters.usage *= USAGE_DECREASE_FACTOR;
-	}
-
-	qsort(entries, i, sizeof(pgssEntry *), entry_cmp);
-	nvictims = Max(10, i * USAGE_DEALLOC_PERCENT / 100);
-	nvictims = Min(nvictims, i);
-
-	for (i = 0; i < nvictims; i++)
-	{
-		hash_search(pgss_hash, &entries[i]->key, HASH_REMOVE, NULL);
-	}
-
-	pfree(entries);
-}
-
-/*
- * Release all entries.
- */
-static void
-entry_reset(void)
-{
-	HASH_SEQ_STATUS hash_seq;
-	pgssEntry  *entry;
-
-	LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
-
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
-	{
-		hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
-	}
-
-	LWLockRelease(pgss->lock);
-}
diff --git a/contrib/pg_stat_statements/pg_stat_statements.control b/contrib/pg_stat_statements/pg_stat_statements.control
deleted file mode 100644
index 6f9a947..0000000
--- a/contrib/pg_stat_statements/pg_stat_statements.control
+++ /dev/null
@@ -1,5 +0,0 @@
-# pg_stat_statements extension
-comment = 'track execution statistics of all SQL statements executed'
-default_version = '1.0'
-module_pathname = '$libdir/pg_stat_statements'
-relocatable = true
diff --git a/contrib/pgrowlocks/Makefile b/contrib/pgrowlocks/Makefile
deleted file mode 100644
index f56389b..0000000
--- a/contrib/pgrowlocks/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-# contrib/pgrowlocks/Makefile
-
-MODULE_big	= pgrowlocks
-OBJS		= pgrowlocks.o
-
-EXTENSION = pgrowlocks
-DATA = pgrowlocks--1.0.sql pgrowlocks--unpackaged--1.0.sql
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/pgrowlocks
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
diff --git a/contrib/pgrowlocks/pgrowlocks--1.0.sql b/contrib/pgrowlocks/pgrowlocks--1.0.sql
deleted file mode 100644
index 0b60fdc..0000000
--- a/contrib/pgrowlocks/pgrowlocks--1.0.sql
+++ /dev/null
@@ -1,12 +0,0 @@
-/* contrib/pgrowlocks/pgrowlocks--1.0.sql */
-
-CREATE FUNCTION pgrowlocks(IN relname text,
-    OUT locked_row TID,		-- row TID
-    OUT lock_type TEXT,		-- lock type
-    OUT locker XID,		-- locking XID
-    OUT multi bool,		-- multi XID?
-    OUT xids xid[],		-- multi XIDs
-    OUT pids INTEGER[])		-- locker's process id
-RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'pgrowlocks'
-LANGUAGE C STRICT;
diff --git a/contrib/pgrowlocks/pgrowlocks--unpackaged--1.0.sql b/contrib/pgrowlocks/pgrowlocks--unpackaged--1.0.sql
deleted file mode 100644
index 2d9d1ee..0000000
--- a/contrib/pgrowlocks/pgrowlocks--unpackaged--1.0.sql
+++ /dev/null
@@ -1,3 +0,0 @@
-/* contrib/pgrowlocks/pgrowlocks--unpackaged--1.0.sql */
-
-ALTER EXTENSION pgrowlocks ADD function pgrowlocks(text);
diff --git a/contrib/pgrowlocks/pgrowlocks.c b/contrib/pgrowlocks/pgrowlocks.c
deleted file mode 100644
index 302bb5c..0000000
--- a/contrib/pgrowlocks/pgrowlocks.c
+++ /dev/null
@@ -1,220 +0,0 @@
-/*
- * contrib/pgrowlocks/pgrowlocks.c
- *
- * Copyright (c) 2005-2006	Tatsuo Ishii
- *
- * Permission to use, copy, modify, and distribute this software and
- * its documentation for any purpose, without fee, and without a
- * written agreement is hereby granted, provided that the above
- * copyright notice and this paragraph and the following two
- * paragraphs appear in all copies.
- *
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
- * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
- * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
- * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
- * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
- * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- */
-
-#include "postgres.h"
-
-#include "access/heapam.h"
-#include "access/multixact.h"
-#include "access/relscan.h"
-#include "access/xact.h"
-#include "catalog/namespace.h"
-#include "funcapi.h"
-#include "miscadmin.h"
-#include "storage/bufmgr.h"
-#include "storage/procarray.h"
-#include "utils/acl.h"
-#include "utils/builtins.h"
-#include "utils/tqual.h"
-
-
-PG_MODULE_MAGIC;
-
-PG_FUNCTION_INFO_V1(pgrowlocks);
-
-extern Datum pgrowlocks(PG_FUNCTION_ARGS);
-
-/* ----------
- * pgrowlocks:
- * returns tids of rows being locked
- * ----------
- */
-
-#define NCHARS 32
-
-typedef struct
-{
-	Relation	rel;
-	HeapScanDesc scan;
-	int			ncolumns;
-} MyData;
-
-Datum
-pgrowlocks(PG_FUNCTION_ARGS)
-{
-	FuncCallContext *funcctx;
-	HeapScanDesc scan;
-	HeapTuple	tuple;
-	TupleDesc	tupdesc;
-	AttInMetadata *attinmeta;
-	Datum		result;
-	MyData	   *mydata;
-	Relation	rel;
-
-	if (SRF_IS_FIRSTCALL())
-	{
-		text	   *relname;
-		RangeVar   *relrv;
-		MemoryContext oldcontext;
-		AclResult	aclresult;
-
-		funcctx = SRF_FIRSTCALL_INIT();
-		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
-
-		/* Build a tuple descriptor for our result type */
-		if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
-			elog(ERROR, "return type must be a row type");
-
-		attinmeta = TupleDescGetAttInMetadata(tupdesc);
-		funcctx->attinmeta = attinmeta;
-
-		relname = PG_GETARG_TEXT_P(0);
-		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-		rel = heap_openrv(relrv, AccessShareLock);
-
-		/* check permissions: must have SELECT on table */
-		aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
-									  ACL_SELECT);
-		if (aclresult != ACLCHECK_OK)
-			aclcheck_error(aclresult, ACL_KIND_CLASS,
-						   RelationGetRelationName(rel));
-
-		scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
-		mydata = palloc(sizeof(*mydata));
-		mydata->rel = rel;
-		mydata->scan = scan;
-		mydata->ncolumns = tupdesc->natts;
-		funcctx->user_fctx = mydata;
-
-		MemoryContextSwitchTo(oldcontext);
-	}
-
-	funcctx = SRF_PERCALL_SETUP();
-	attinmeta = funcctx->attinmeta;
-	mydata = (MyData *) funcctx->user_fctx;
-	scan = mydata->scan;
-
-	/* scan the relation */
-	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
-	{
-		/* must hold a buffer lock to call HeapTupleSatisfiesUpdate */
-		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
-
-		if (HeapTupleSatisfiesUpdate(tuple->t_data,
-									 GetCurrentCommandId(false),
-									 scan->rs_cbuf) == HeapTupleBeingUpdated)
-		{
-
-			char	  **values;
-			int			i;
-
-			values = (char **) palloc(mydata->ncolumns * sizeof(char *));
-
-			i = 0;
-			values[i++] = (char *) DirectFunctionCall1(tidout, PointerGetDatum(&tuple->t_self));
-
-			if (tuple->t_data->t_infomask & HEAP_XMAX_SHARED_LOCK)
-				values[i++] = pstrdup("Shared");
-			else
-				values[i++] = pstrdup("Exclusive");
-			values[i] = palloc(NCHARS * sizeof(char));
-			snprintf(values[i++], NCHARS, "%d", HeapTupleHeaderGetXmax(tuple->t_data));
-			if (tuple->t_data->t_infomask & HEAP_XMAX_IS_MULTI)
-			{
-				TransactionId *xids;
-				int			nxids;
-				int			j;
-				int			isValidXid = 0;		/* any valid xid ever exists? */
-
-				values[i++] = pstrdup("true");
-				nxids = GetMultiXactIdMembers(HeapTupleHeaderGetXmax(tuple->t_data), &xids);
-				if (nxids == -1)
-				{
-					elog(ERROR, "GetMultiXactIdMembers returns error");
-				}
-
-				values[i] = palloc(NCHARS * nxids);
-				values[i + 1] = palloc(NCHARS * nxids);
-				strcpy(values[i], "{");
-				strcpy(values[i + 1], "{");
-
-				for (j = 0; j < nxids; j++)
-				{
-					char		buf[NCHARS];
-
-					if (TransactionIdIsInProgress(xids[j]))
-					{
-						if (isValidXid)
-						{
-							strcat(values[i], ",");
-							strcat(values[i + 1], ",");
-						}
-						snprintf(buf, NCHARS, "%d", xids[j]);
-						strcat(values[i], buf);
-						snprintf(buf, NCHARS, "%d", BackendXidGetPid(xids[j]));
-						strcat(values[i + 1], buf);
-
-						isValidXid = 1;
-					}
-				}
-
-				strcat(values[i], "}");
-				strcat(values[i + 1], "}");
-				i++;
-			}
-			else
-			{
-				values[i++] = pstrdup("false");
-				values[i] = palloc(NCHARS * sizeof(char));
-				snprintf(values[i++], NCHARS, "{%d}", HeapTupleHeaderGetXmax(tuple->t_data));
-
-				values[i] = palloc(NCHARS * sizeof(char));
-				snprintf(values[i++], NCHARS, "{%d}", BackendXidGetPid(HeapTupleHeaderGetXmax(tuple->t_data)));
-			}
-
-			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
-
-			/* build a tuple */
-			tuple = BuildTupleFromCStrings(attinmeta, values);
-
-			/* make the tuple into a datum */
-			result = HeapTupleGetDatum(tuple);
-
-			/* Clean up */
-			for (i = 0; i < mydata->ncolumns; i++)
-				pfree(values[i]);
-			pfree(values);
-
-			SRF_RETURN_NEXT(funcctx, result);
-		}
-		else
-		{
-			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
-		}
-	}
-
-	heap_endscan(scan);
-	heap_close(mydata->rel, AccessShareLock);
-
-	SRF_RETURN_DONE(funcctx);
-}
diff --git a/contrib/pgrowlocks/pgrowlocks.control b/contrib/pgrowlocks/pgrowlocks.control
deleted file mode 100644
index a6ba164..0000000
--- a/contrib/pgrowlocks/pgrowlocks.control
+++ /dev/null
@@ -1,5 +0,0 @@
-# pgrowlocks extension
-comment = 'show row-level locking information'
-default_version = '1.0'
-module_pathname = '$libdir/pgrowlocks'
-relocatable = true
diff --git a/contrib/pgstattuple/Makefile b/contrib/pgstattuple/Makefile
deleted file mode 100644
index 13b8709..0000000
--- a/contrib/pgstattuple/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-# contrib/pgstattuple/Makefile
-
-MODULE_big	= pgstattuple
-OBJS		= pgstattuple.o pgstatindex.o
-
-EXTENSION = pgstattuple
-DATA = pgstattuple--1.0.sql pgstattuple--unpackaged--1.0.sql
-
-ifdef USE_PGXS
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
-else
-subdir = contrib/pgstattuple
-top_builddir = ../..
-include $(top_builddir)/src/Makefile.global
-include $(top_srcdir)/contrib/contrib-global.mk
-endif
diff --git a/contrib/pgstattuple/pgstatindex.c b/contrib/pgstattuple/pgstatindex.c
deleted file mode 100644
index fd2cc92..0000000
--- a/contrib/pgstattuple/pgstatindex.c
+++ /dev/null
@@ -1,282 +0,0 @@
-/*
- * contrib/pgstattuple/pgstatindex.c
- *
- *
- * pgstatindex
- *
- * Copyright (c) 2006 Satoshi Nagayasu <nagayasus@nttdata.co.jp>
- *
- * Permission to use, copy, modify, and distribute this software and
- * its documentation for any purpose, without fee, and without a
- * written agreement is hereby granted, provided that the above
- * copyright notice and this paragraph and the following two
- * paragraphs appear in all copies.
- *
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
- * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
- * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
- * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
- * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
- * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- */
-
-#include "postgres.h"
-
-#include "access/heapam.h"
-#include "access/nbtree.h"
-#include "catalog/namespace.h"
-#include "funcapi.h"
-#include "miscadmin.h"
-#include "storage/bufmgr.h"
-#include "utils/builtins.h"
-
-
-extern Datum pgstatindex(PG_FUNCTION_ARGS);
-extern Datum pg_relpages(PG_FUNCTION_ARGS);
-
-PG_FUNCTION_INFO_V1(pgstatindex);
-PG_FUNCTION_INFO_V1(pg_relpages);
-
-#define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
-#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
-
-#define CHECK_PAGE_OFFSET_RANGE(pg, offnum) { \
-		if ( !(FirstOffsetNumber <= (offnum) && \
-						(offnum) <= PageGetMaxOffsetNumber(pg)) ) \
-			 elog(ERROR, "page offset number out of range"); }
-
-/* note: BlockNumber is unsigned, hence can't be negative */
-#define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
-		if ( RelationGetNumberOfBlocks(rel) <= (BlockNumber) (blkno) ) \
-			 elog(ERROR, "block number out of range"); }
-
-/* ------------------------------------------------
- * A structure for a whole btree index statistics
- * used by pgstatindex().
- * ------------------------------------------------
- */
-typedef struct BTIndexStat
-{
-	uint32		version;
-	uint32		level;
-	BlockNumber root_blkno;
-
-	uint64		root_pages;
-	uint64		internal_pages;
-	uint64		leaf_pages;
-	uint64		empty_pages;
-	uint64		deleted_pages;
-
-	uint64		max_avail;
-	uint64		free_space;
-
-	uint64		fragments;
-} BTIndexStat;
-
-/* ------------------------------------------------------
- * pgstatindex()
- *
- * Usage: SELECT * FROM pgstatindex('t1_pkey');
- * ------------------------------------------------------
- */
-Datum
-pgstatindex(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	Relation	rel;
-	RangeVar   *relrv;
-	Datum		result;
-	BlockNumber nblocks;
-	BlockNumber blkno;
-	BTIndexStat indexStat;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use pgstattuple functions"))));
-
-	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-	rel = relation_openrv(relrv, AccessShareLock);
-
-	if (!IS_INDEX(rel) || !IS_BTREE(rel))
-		elog(ERROR, "relation \"%s\" is not a btree index",
-			 RelationGetRelationName(rel));
-
-	/*
-	 * Reject attempts to read non-local temporary relations; we would be
-	 * likely to get wrong data since we have no visibility into the owning
-	 * session's local buffers.
-	 */
-	if (RELATION_IS_OTHER_TEMP(rel))
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot access temporary tables of other sessions")));
-
-	/*
-	 * Read metapage
-	 */
-	{
-		Buffer		buffer = ReadBuffer(rel, 0);
-		Page		page = BufferGetPage(buffer);
-		BTMetaPageData *metad = BTPageGetMeta(page);
-
-		indexStat.version = metad->btm_version;
-		indexStat.level = metad->btm_level;
-		indexStat.root_blkno = metad->btm_root;
-
-		ReleaseBuffer(buffer);
-	}
-
-	/* -- init counters -- */
-	indexStat.root_pages = 0;
-	indexStat.internal_pages = 0;
-	indexStat.leaf_pages = 0;
-	indexStat.empty_pages = 0;
-	indexStat.deleted_pages = 0;
-
-	indexStat.max_avail = 0;
-	indexStat.free_space = 0;
-
-	indexStat.fragments = 0;
-
-	/*
-	 * Scan all blocks except the metapage
-	 */
-	nblocks = RelationGetNumberOfBlocks(rel);
-
-	for (blkno = 1; blkno < nblocks; blkno++)
-	{
-		Buffer		buffer;
-		Page		page;
-		BTPageOpaque opaque;
-
-		/* Read and lock buffer */
-		buffer = ReadBuffer(rel, blkno);
-		LockBuffer(buffer, BUFFER_LOCK_SHARE);
-
-		page = BufferGetPage(buffer);
-		opaque = (BTPageOpaque) PageGetSpecialPointer(page);
-
-		/* Determine page type, and update totals */
-
-		if (P_ISLEAF(opaque))
-		{
-			int			max_avail;
-
-			max_avail = BLCKSZ - (BLCKSZ - ((PageHeader) page)->pd_special + SizeOfPageHeaderData);
-			indexStat.max_avail += max_avail;
-			indexStat.free_space += PageGetFreeSpace(page);
-
-			indexStat.leaf_pages++;
-
-			/*
-			 * If the next leaf is on an earlier block, it means a
-			 * fragmentation.
-			 */
-			if (opaque->btpo_next != P_NONE && opaque->btpo_next < blkno)
-				indexStat.fragments++;
-		}
-		else if (P_ISDELETED(opaque))
-			indexStat.deleted_pages++;
-		else if (P_IGNORE(opaque))
-			indexStat.empty_pages++;
-		else if (P_ISROOT(opaque))
-			indexStat.root_pages++;
-		else
-			indexStat.internal_pages++;
-
-		/* Unlock and release buffer */
-		LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
-		ReleaseBuffer(buffer);
-	}
-
-	relation_close(rel, AccessShareLock);
-
-	/*----------------------------
-	 * Build a result tuple
-	 *----------------------------
-	 */
-	{
-		TupleDesc	tupleDesc;
-		int			j;
-		char	   *values[10];
-		HeapTuple	tuple;
-
-		/* Build a tuple descriptor for our result type */
-		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
-			elog(ERROR, "return type must be a row type");
-
-		j = 0;
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%d", indexStat.version);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%d", indexStat.level);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, INT64_FORMAT,
-				 (indexStat.root_pages +
-				  indexStat.leaf_pages +
-				  indexStat.internal_pages +
-				  indexStat.deleted_pages +
-				  indexStat.empty_pages) * BLCKSZ);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%u", indexStat.root_blkno);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, INT64_FORMAT, indexStat.internal_pages);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, INT64_FORMAT, indexStat.leaf_pages);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, INT64_FORMAT, indexStat.empty_pages);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, INT64_FORMAT, indexStat.deleted_pages);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%.2f", 100.0 - (double) indexStat.free_space / (double) indexStat.max_avail * 100.0);
-		values[j] = palloc(32);
-		snprintf(values[j++], 32, "%.2f", (double) indexStat.fragments / (double) indexStat.leaf_pages * 100.0);
-
-		tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
-									   values);
-
-		result = HeapTupleGetDatum(tuple);
-	}
-
-	PG_RETURN_DATUM(result);
-}
-
-/* --------------------------------------------------------
- * pg_relpages()
- *
- * Get the number of pages of the table/index.
- *
- * Usage: SELECT pg_relpages('t1');
- *		  SELECT pg_relpages('t1_pkey');
- * --------------------------------------------------------
- */
-Datum
-pg_relpages(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	int64		relpages;
-	Relation	rel;
-	RangeVar   *relrv;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use pgstattuple functions"))));
-
-	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-	rel = relation_openrv(relrv, AccessShareLock);
-
-	/* note: this will work OK on non-local temp tables */
-
-	relpages = RelationGetNumberOfBlocks(rel);
-
-	relation_close(rel, AccessShareLock);
-
-	PG_RETURN_INT64(relpages);
-}
diff --git a/contrib/pgstattuple/pgstattuple--1.0.sql b/contrib/pgstattuple/pgstattuple--1.0.sql
deleted file mode 100644
index 83445ec..0000000
--- a/contrib/pgstattuple/pgstattuple--1.0.sql
+++ /dev/null
@@ -1,46 +0,0 @@
-/* contrib/pgstattuple/pgstattuple--1.0.sql */
-
-CREATE FUNCTION pgstattuple(IN relname text,
-    OUT table_len BIGINT,		-- physical table length in bytes
-    OUT tuple_count BIGINT,		-- number of live tuples
-    OUT tuple_len BIGINT,		-- total tuples length in bytes
-    OUT tuple_percent FLOAT8,		-- live tuples in %
-    OUT dead_tuple_count BIGINT,	-- number of dead tuples
-    OUT dead_tuple_len BIGINT,		-- total dead tuples length in bytes
-    OUT dead_tuple_percent FLOAT8,	-- dead tuples in %
-    OUT free_space BIGINT,		-- free space in bytes
-    OUT free_percent FLOAT8)		-- free space in %
-AS 'MODULE_PATHNAME', 'pgstattuple'
-LANGUAGE C STRICT;
-
-CREATE FUNCTION pgstattuple(IN reloid oid,
-    OUT table_len BIGINT,		-- physical table length in bytes
-    OUT tuple_count BIGINT,		-- number of live tuples
-    OUT tuple_len BIGINT,		-- total tuples length in bytes
-    OUT tuple_percent FLOAT8,		-- live tuples in %
-    OUT dead_tuple_count BIGINT,	-- number of dead tuples
-    OUT dead_tuple_len BIGINT,		-- total dead tuples length in bytes
-    OUT dead_tuple_percent FLOAT8,	-- dead tuples in %
-    OUT free_space BIGINT,		-- free space in bytes
-    OUT free_percent FLOAT8)		-- free space in %
-AS 'MODULE_PATHNAME', 'pgstattuplebyid'
-LANGUAGE C STRICT;
-
-CREATE FUNCTION pgstatindex(IN relname text,
-    OUT version INT,
-    OUT tree_level INT,
-    OUT index_size BIGINT,
-    OUT root_block_no BIGINT,
-    OUT internal_pages BIGINT,
-    OUT leaf_pages BIGINT,
-    OUT empty_pages BIGINT,
-    OUT deleted_pages BIGINT,
-    OUT avg_leaf_density FLOAT8,
-    OUT leaf_fragmentation FLOAT8)
-AS 'MODULE_PATHNAME', 'pgstatindex'
-LANGUAGE C STRICT;
-
-CREATE FUNCTION pg_relpages(IN relname text)
-RETURNS BIGINT
-AS 'MODULE_PATHNAME', 'pg_relpages'
-LANGUAGE C STRICT;
diff --git a/contrib/pgstattuple/pgstattuple--unpackaged--1.0.sql b/contrib/pgstattuple/pgstattuple--unpackaged--1.0.sql
deleted file mode 100644
index 3cfb8db..0000000
--- a/contrib/pgstattuple/pgstattuple--unpackaged--1.0.sql
+++ /dev/null
@@ -1,6 +0,0 @@
-/* contrib/pgstattuple/pgstattuple--unpackaged--1.0.sql */
-
-ALTER EXTENSION pgstattuple ADD function pgstattuple(text);
-ALTER EXTENSION pgstattuple ADD function pgstattuple(oid);
-ALTER EXTENSION pgstattuple ADD function pgstatindex(text);
-ALTER EXTENSION pgstattuple ADD function pg_relpages(text);
diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
deleted file mode 100644
index e5ddd87..0000000
--- a/contrib/pgstattuple/pgstattuple.c
+++ /dev/null
@@ -1,518 +0,0 @@
-/*
- * contrib/pgstattuple/pgstattuple.c
- *
- * Copyright (c) 2001,2002	Tatsuo Ishii
- *
- * Permission to use, copy, modify, and distribute this software and
- * its documentation for any purpose, without fee, and without a
- * written agreement is hereby granted, provided that the above
- * copyright notice and this paragraph and the following two
- * paragraphs appear in all copies.
- *
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
- * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
- * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
- * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
- * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
- * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- */
-
-#include "postgres.h"
-
-#include "access/gist_private.h"
-#include "access/hash.h"
-#include "access/nbtree.h"
-#include "access/relscan.h"
-#include "catalog/namespace.h"
-#include "funcapi.h"
-#include "miscadmin.h"
-#include "storage/bufmgr.h"
-#include "storage/lmgr.h"
-#include "utils/builtins.h"
-#include "utils/tqual.h"
-
-
-PG_MODULE_MAGIC;
-
-PG_FUNCTION_INFO_V1(pgstattuple);
-PG_FUNCTION_INFO_V1(pgstattuplebyid);
-
-extern Datum pgstattuple(PG_FUNCTION_ARGS);
-extern Datum pgstattuplebyid(PG_FUNCTION_ARGS);
-
-/*
- * struct pgstattuple_type
- *
- * tuple_percent, dead_tuple_percent and free_percent are computable,
- * so not defined here.
- */
-typedef struct pgstattuple_type
-{
-	uint64		table_len;
-	uint64		tuple_count;
-	uint64		tuple_len;
-	uint64		dead_tuple_count;
-	uint64		dead_tuple_len;
-	uint64		free_space;		/* free/reusable space in bytes */
-} pgstattuple_type;
-
-typedef void (*pgstat_page) (pgstattuple_type *, Relation, BlockNumber);
-
-static Datum build_pgstattuple_type(pgstattuple_type *stat,
-					   FunctionCallInfo fcinfo);
-static Datum pgstat_relation(Relation rel, FunctionCallInfo fcinfo);
-static Datum pgstat_heap(Relation rel, FunctionCallInfo fcinfo);
-static void pgstat_btree_page(pgstattuple_type *stat,
-				  Relation rel, BlockNumber blkno);
-static void pgstat_hash_page(pgstattuple_type *stat,
-				 Relation rel, BlockNumber blkno);
-static void pgstat_gist_page(pgstattuple_type *stat,
-				 Relation rel, BlockNumber blkno);
-static Datum pgstat_index(Relation rel, BlockNumber start,
-			 pgstat_page pagefn, FunctionCallInfo fcinfo);
-static void pgstat_index_page(pgstattuple_type *stat, Page page,
-				  OffsetNumber minoff, OffsetNumber maxoff);
-
-/*
- * build_pgstattuple_type -- build a pgstattuple_type tuple
- */
-static Datum
-build_pgstattuple_type(pgstattuple_type *stat, FunctionCallInfo fcinfo)
-{
-#define NCOLUMNS	9
-#define NCHARS		32
-
-	HeapTuple	tuple;
-	char	   *values[NCOLUMNS];
-	char		values_buf[NCOLUMNS][NCHARS];
-	int			i;
-	double		tuple_percent;
-	double		dead_tuple_percent;
-	double		free_percent;	/* free/reusable space in % */
-	TupleDesc	tupdesc;
-	AttInMetadata *attinmeta;
-
-	/* Build a tuple descriptor for our result type */
-	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
-		elog(ERROR, "return type must be a row type");
-
-	/*
-	 * Generate attribute metadata needed later to produce tuples from raw C
-	 * strings
-	 */
-	attinmeta = TupleDescGetAttInMetadata(tupdesc);
-
-	if (stat->table_len == 0)
-	{
-		tuple_percent = 0.0;
-		dead_tuple_percent = 0.0;
-		free_percent = 0.0;
-	}
-	else
-	{
-		tuple_percent = 100.0 * stat->tuple_len / stat->table_len;
-		dead_tuple_percent = 100.0 * stat->dead_tuple_len / stat->table_len;
-		free_percent = 100.0 * stat->free_space / stat->table_len;
-	}
-
-	/*
-	 * Prepare a values array for constructing the tuple. This should be an
-	 * array of C strings which will be processed later by the appropriate
-	 * "in" functions.
-	 */
-	for (i = 0; i < NCOLUMNS; i++)
-		values[i] = values_buf[i];
-	i = 0;
-	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->table_len);
-	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->tuple_count);
-	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->tuple_len);
-	snprintf(values[i++], NCHARS, "%.2f", tuple_percent);
-	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->dead_tuple_count);
-	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->dead_tuple_len);
-	snprintf(values[i++], NCHARS, "%.2f", dead_tuple_percent);
-	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->free_space);
-	snprintf(values[i++], NCHARS, "%.2f", free_percent);
-
-	/* build a tuple */
-	tuple = BuildTupleFromCStrings(attinmeta, values);
-
-	/* make the tuple into a datum */
-	return HeapTupleGetDatum(tuple);
-}
-
-/* ----------
- * pgstattuple:
- * returns live/dead tuples info
- *
- * C FUNCTION definition
- * pgstattuple(text) returns pgstattuple_type
- * see pgstattuple.sql for pgstattuple_type
- * ----------
- */
-
-Datum
-pgstattuple(PG_FUNCTION_ARGS)
-{
-	text	   *relname = PG_GETARG_TEXT_P(0);
-	RangeVar   *relrv;
-	Relation	rel;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use pgstattuple functions"))));
-
-	/* open relation */
-	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-	rel = relation_openrv(relrv, AccessShareLock);
-
-	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
-}
-
-Datum
-pgstattuplebyid(PG_FUNCTION_ARGS)
-{
-	Oid			relid = PG_GETARG_OID(0);
-	Relation	rel;
-
-	if (!superuser())
-		ereport(ERROR,
-				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be superuser to use pgstattuple functions"))));
-
-	/* open relation */
-	rel = relation_open(relid, AccessShareLock);
-
-	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
-}
-
-/*
- * pgstat_relation
- */
-static Datum
-pgstat_relation(Relation rel, FunctionCallInfo fcinfo)
-{
-	const char *err;
-
-	/*
-	 * Reject attempts to read non-local temporary relations; we would be
-	 * likely to get wrong data since we have no visibility into the owning
-	 * session's local buffers.
-	 */
-	if (RELATION_IS_OTHER_TEMP(rel))
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot access temporary tables of other sessions")));
-
-	switch (rel->rd_rel->relkind)
-	{
-		case RELKIND_RELATION:
-		case RELKIND_TOASTVALUE:
-		case RELKIND_UNCATALOGED:
-		case RELKIND_SEQUENCE:
-			return pgstat_heap(rel, fcinfo);
-		case RELKIND_INDEX:
-			switch (rel->rd_rel->relam)
-			{
-				case BTREE_AM_OID:
-					return pgstat_index(rel, BTREE_METAPAGE + 1,
-										pgstat_btree_page, fcinfo);
-				case HASH_AM_OID:
-					return pgstat_index(rel, HASH_METAPAGE + 1,
-										pgstat_hash_page, fcinfo);
-				case GIST_AM_OID:
-					return pgstat_index(rel, GIST_ROOT_BLKNO + 1,
-										pgstat_gist_page, fcinfo);
-				case GIN_AM_OID:
-					err = "gin index";
-					break;
-				default:
-					err = "unknown index";
-					break;
-			}
-			break;
-		case RELKIND_VIEW:
-			err = "view";
-			break;
-		case RELKIND_COMPOSITE_TYPE:
-			err = "composite type";
-			break;
-		case RELKIND_FOREIGN_TABLE:
-			err = "foreign table";
-			break;
-		default:
-			err = "unknown";
-			break;
-	}
-
-	ereport(ERROR,
-			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-			 errmsg("\"%s\" (%s) is not supported",
-					RelationGetRelationName(rel), err)));
-	return 0;					/* should not happen */
-}
-
-/*
- * pgstat_heap -- returns live/dead tuples info in a heap
- */
-static Datum
-pgstat_heap(Relation rel, FunctionCallInfo fcinfo)
-{
-	HeapScanDesc scan;
-	HeapTuple	tuple;
-	BlockNumber nblocks;
-	BlockNumber block = 0;		/* next block to count free space in */
-	BlockNumber tupblock;
-	Buffer		buffer;
-	pgstattuple_type stat = {0};
-
-	/* Disable syncscan because we assume we scan from block zero upwards */
-	scan = heap_beginscan_strat(rel, SnapshotAny, 0, NULL, true, false);
-
-	nblocks = scan->rs_nblocks; /* # blocks to be scanned */
-
-	/* scan the relation */
-	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
-	{
-		CHECK_FOR_INTERRUPTS();
-
-		/* must hold a buffer lock to call HeapTupleSatisfiesVisibility */
-		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
-
-		if (HeapTupleSatisfiesVisibility(tuple, SnapshotNow, scan->rs_cbuf))
-		{
-			stat.tuple_len += tuple->t_len;
-			stat.tuple_count++;
-		}
-		else
-		{
-			stat.dead_tuple_len += tuple->t_len;
-			stat.dead_tuple_count++;
-		}
-
-		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
-
-		/*
-		 * To avoid physically reading the table twice, try to do the
-		 * free-space scan in parallel with the heap scan.	However,
-		 * heap_getnext may find no tuples on a given page, so we cannot
-		 * simply examine the pages returned by the heap scan.
-		 */
-		tupblock = BlockIdGetBlockNumber(&tuple->t_self.ip_blkid);
-
-		while (block <= tupblock)
-		{
-			CHECK_FOR_INTERRUPTS();
-
-			buffer = ReadBuffer(rel, block);
-			LockBuffer(buffer, BUFFER_LOCK_SHARE);
-			stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
-			UnlockReleaseBuffer(buffer);
-			block++;
-		}
-	}
-	heap_endscan(scan);
-
-	while (block < nblocks)
-	{
-		CHECK_FOR_INTERRUPTS();
-
-		buffer = ReadBuffer(rel, block);
-		LockBuffer(buffer, BUFFER_LOCK_SHARE);
-		stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
-		UnlockReleaseBuffer(buffer);
-		block++;
-	}
-
-	relation_close(rel, AccessShareLock);
-
-	stat.table_len = (uint64) nblocks *BLCKSZ;
-
-	return build_pgstattuple_type(&stat, fcinfo);
-}
-
-/*
- * pgstat_btree_page -- check tuples in a btree page
- */
-static void
-pgstat_btree_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno)
-{
-	Buffer		buf;
-	Page		page;
-
-	buf = ReadBuffer(rel, blkno);
-	LockBuffer(buf, BT_READ);
-	page = BufferGetPage(buf);
-
-	/* Page is valid, see what to do with it */
-	if (PageIsNew(page))
-	{
-		/* fully empty page */
-		stat->free_space += BLCKSZ;
-	}
-	else
-	{
-		BTPageOpaque opaque;
-
-		opaque = (BTPageOpaque) PageGetSpecialPointer(page);
-		if (opaque->btpo_flags & (BTP_DELETED | BTP_HALF_DEAD))
-		{
-			/* recyclable page */
-			stat->free_space += BLCKSZ;
-		}
-		else if (P_ISLEAF(opaque))
-		{
-			pgstat_index_page(stat, page, P_FIRSTDATAKEY(opaque),
-							  PageGetMaxOffsetNumber(page));
-		}
-		else
-		{
-			/* root or node */
-		}
-	}
-
-	_bt_relbuf(rel, buf);
-}
-
-/*
- * pgstat_hash_page -- check tuples in a hash page
- */
-static void
-pgstat_hash_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno)
-{
-	Buffer		buf;
-	Page		page;
-
-	_hash_getlock(rel, blkno, HASH_SHARE);
-	buf = _hash_getbuf(rel, blkno, HASH_READ, 0);
-	page = BufferGetPage(buf);
-
-	if (PageGetSpecialSize(page) == MAXALIGN(sizeof(HashPageOpaqueData)))
-	{
-		HashPageOpaque opaque;
-
-		opaque = (HashPageOpaque) PageGetSpecialPointer(page);
-		switch (opaque->hasho_flag)
-		{
-			case LH_UNUSED_PAGE:
-				stat->free_space += BLCKSZ;
-				break;
-			case LH_BUCKET_PAGE:
-			case LH_OVERFLOW_PAGE:
-				pgstat_index_page(stat, page, FirstOffsetNumber,
-								  PageGetMaxOffsetNumber(page));
-				break;
-			case LH_BITMAP_PAGE:
-			case LH_META_PAGE:
-			default:
-				break;
-		}
-	}
-	else
-	{
-		/* maybe corrupted */
-	}
-
-	_hash_relbuf(rel, buf);
-	_hash_droplock(rel, blkno, HASH_SHARE);
-}
-
-/*
- * pgstat_gist_page -- check tuples in a gist page
- */
-static void
-pgstat_gist_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno)
-{
-	Buffer		buf;
-	Page		page;
-
-	buf = ReadBuffer(rel, blkno);
-	LockBuffer(buf, GIST_SHARE);
-	gistcheckpage(rel, buf);
-	page = BufferGetPage(buf);
-
-	if (GistPageIsLeaf(page))
-	{
-		pgstat_index_page(stat, page, FirstOffsetNumber,
-						  PageGetMaxOffsetNumber(page));
-	}
-	else
-	{
-		/* root or node */
-	}
-
-	UnlockReleaseBuffer(buf);
-}
-
-/*
- * pgstat_index -- returns live/dead tuples info in a generic index
- */
-static Datum
-pgstat_index(Relation rel, BlockNumber start, pgstat_page pagefn,
-			 FunctionCallInfo fcinfo)
-{
-	BlockNumber nblocks;
-	BlockNumber blkno;
-	pgstattuple_type stat = {0};
-
-	blkno = start;
-	for (;;)
-	{
-		/* Get the current relation length */
-		LockRelationForExtension(rel, ExclusiveLock);
-		nblocks = RelationGetNumberOfBlocks(rel);
-		UnlockRelationForExtension(rel, ExclusiveLock);
-
-		/* Quit if we've scanned the whole relation */
-		if (blkno >= nblocks)
-		{
-			stat.table_len = (uint64) nblocks *BLCKSZ;
-
-			break;
-		}
-
-		for (; blkno < nblocks; blkno++)
-		{
-			CHECK_FOR_INTERRUPTS();
-
-			pagefn(&stat, rel, blkno);
-		}
-	}
-
-	relation_close(rel, AccessShareLock);
-
-	return build_pgstattuple_type(&stat, fcinfo);
-}
-
-/*
- * pgstat_index_page -- for generic index page
- */
-static void
-pgstat_index_page(pgstattuple_type *stat, Page page,
-				  OffsetNumber minoff, OffsetNumber maxoff)
-{
-	OffsetNumber i;
-
-	stat->free_space += PageGetFreeSpace(page);
-
-	for (i = minoff; i <= maxoff; i = OffsetNumberNext(i))
-	{
-		ItemId		itemid = PageGetItemId(page, i);
-
-		if (ItemIdIsDead(itemid))
-		{
-			stat->dead_tuple_count++;
-			stat->dead_tuple_len += ItemIdGetLength(itemid);
-		}
-		else
-		{
-			stat->tuple_count++;
-			stat->tuple_len += ItemIdGetLength(itemid);
-		}
-	}
-}
diff --git a/contrib/pgstattuple/pgstattuple.control b/contrib/pgstattuple/pgstattuple.control
deleted file mode 100644
index 7b5129b..0000000
--- a/contrib/pgstattuple/pgstattuple.control
+++ /dev/null
@@ -1,5 +0,0 @@
-# pgstattuple extension
-comment = 'show tuple-level statistics'
-default_version = '1.0'
-module_pathname = '$libdir/pgstattuple'
-relocatable = true
diff --git a/doc/src/sgml/contrib.sgml b/doc/src/sgml/contrib.sgml
index adf09ca..0d16084 100644
--- a/doc/src/sgml/contrib.sgml
+++ b/doc/src/sgml/contrib.sgml
@@ -89,7 +89,6 @@ CREATE EXTENSION <replaceable>module_name</> FROM unpackaged;
 
  &adminpack;
  &auth-delay;
- &auto-explain;
  &btree-gin;
  &btree-gist;
  &chkpass;
@@ -109,17 +108,11 @@ CREATE EXTENSION <replaceable>module_name</> FROM unpackaged;
  &lo;
  &ltree;
  &oid2name;
- &pageinspect;
  &passwordcheck;
  &pgarchivecleanup;
  &pgbench;
- &pgbuffercache;
  &pgcrypto;
- &pgfreespacemap;
- &pgrowlocks;
  &pgstandby;
- &pgstatstatements;
- &pgstattuple;
  &pgtestfsync;
  &pgtrgm;
  &pgupgrade;
diff --git a/doc/src/sgml/extensions.sgml b/doc/src/sgml/extensions.sgml
new file mode 100644
index 0000000..eea69c3
--- /dev/null
+++ b/doc/src/sgml/extensions.sgml
@@ -0,0 +1,77 @@
+<!-- doc/src/sgml/extensions.sgml -->
+
+<appendix id="extensions">
+ <title>Core Extensions</title>
+
+ <para>
+ 
+  It is difficult to manage all of the components to
+  <productname>PostgreSQL</productname> without making the database core
+  larger than it must be.  But many enhancements can be efficiently developed
+  using the facilites normally intended for adding external modules. 
+  This appendix contains information regarding core extensions that are
+  built and included with a standard installation of PostgreSQL.  These
+  core extensions supply useful features in areas such as database diagnostics
+  and performance monitoring.
+ </para>
+
+ <para>  
+  Some of these features could instead be made available as built-in functions.
+  Providing them as extension modules instead reduces the amount of code to be
+  maintained in the main database.  It also serves as an example of how
+  powerful the extension features described in <xref linkend="extend"> are.  It
+  is possible to write your own extensions of similar utility to those listed
+  here, and to use these as examples for doing so.
+ </para>
+
+ <para>
+  To make use of one of these extensions, you need to register the new SQL
+  objects in the database system.  This is done by executing a
+  <xref linkend="sql-createextension"> command.  In a fresh database,
+  you can simply do
+
+<programlisting>
+CREATE EXTENSION <replaceable>module_name</>;
+</programlisting>
+
+  This command must be run by a database superuser.  This registers the
+  new SQL objects in the current database only, so you need to run this
+  command in each database that you want
+  the module's facilities to be available in.  Alternatively, run it in
+  database <literal>template1</> so that the extension will be copied into
+  subsequently-created databases by default.
+ </para>
+
+ <para>
+  Many modules allow you to install their objects in a schema of your
+  choice.  To do that, add <literal>SCHEMA
+  <replaceable>schema_name</></literal> to the <command>CREATE EXTENSION</>
+  command.  By default, the objects will be placed in your current creation
+  target schema, typically <literal>public</>.
+ </para>
+
+ <para>
+  If your database was brought forward by dump and reload from a pre-9.1
+  version of <productname>PostgreSQL</>, and you had been using the pre-9.1
+  version of the module in it, you should instead do
+
+<programlisting>
+CREATE EXTENSION <replaceable>module_name</> FROM unpackaged;
+</programlisting>
+
+  This will update the pre-9.1 objects of the module into a proper
+  <firstterm>extension</> object.  Future updates to the module will be
+  managed by <xref linkend="sql-alterextension">.
+  For more information about extension updates, see
+  <xref linkend="extend-extensions">.
+ </para>
+
+ &auto-explain;
+ &pageinspect;
+ &pgbuffercache;
+ &pgfreespacemap;
+ &pgrowlocks;
+ &pgstatstatements;
+ &pgstattuple;
+
+</appendix>
diff --git a/doc/src/sgml/external-projects.sgml b/doc/src/sgml/external-projects.sgml
index ef516b4..8b12574 100644
--- a/doc/src/sgml/external-projects.sgml
+++ b/doc/src/sgml/external-projects.sgml
@@ -246,9 +246,10 @@
   <para>
    <productname>PostgreSQL</> is designed to be easily extensible. For
    this reason, extensions loaded into the database can function
-   just like features that are built in. The
+   just like features that are built in.  Some <xref linkend="extension">
+   are available in any installation.  The
    <filename>contrib/</> directory shipped with the source code
-   contains several extensions, which are described in
+   contains several optional extensions, which are described in
    <xref linkend="contrib">.  Other extensions are developed
    independently, like <application><ulink
    url="http://www.postgis.org/">PostGIS</ulink></>.  Even
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index ed39e0b..352c6f2 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -91,11 +91,20 @@
 <!ENTITY sources    SYSTEM "sources.sgml">
 <!ENTITY storage    SYSTEM "storage.sgml">
 
+<!-- core extensions -->
+<!ENTITY extensions      SYSTEM "extensions.sgml">
+<!ENTITY auto-explain    SYSTEM "auto-explain.sgml">
+<!ENTITY pageinspect     SYSTEM "pageinspect.sgml">
+<!ENTITY pgbuffercache   SYSTEM "pgbuffercache.sgml">
+<!ENTITY pgfreespacemap  SYSTEM "pgfreespacemap.sgml">
+<!ENTITY pgrowlocks      SYSTEM "pgrowlocks.sgml">
+<!ENTITY pgstatstatements SYSTEM "pgstatstatements.sgml">
+<!ENTITY pgstattuple     SYSTEM "pgstattuple.sgml">
+
 <!-- contrib information -->
 <!ENTITY contrib         SYSTEM "contrib.sgml">
 <!ENTITY adminpack       SYSTEM "adminpack.sgml">
 <!ENTITY auth-delay      SYSTEM "auth-delay.sgml">
-<!ENTITY auto-explain    SYSTEM "auto-explain.sgml">
 <!ENTITY btree-gin       SYSTEM "btree-gin.sgml">
 <!ENTITY btree-gist      SYSTEM "btree-gist.sgml">
 <!ENTITY chkpass         SYSTEM "chkpass.sgml">
@@ -115,17 +124,11 @@
 <!ENTITY lo              SYSTEM "lo.sgml">
 <!ENTITY ltree           SYSTEM "ltree.sgml">
 <!ENTITY oid2name        SYSTEM "oid2name.sgml">
-<!ENTITY pageinspect     SYSTEM "pageinspect.sgml">
 <!ENTITY passwordcheck   SYSTEM "passwordcheck.sgml">
 <!ENTITY pgbench         SYSTEM "pgbench.sgml">
 <!ENTITY pgarchivecleanup SYSTEM "pgarchivecleanup.sgml">
-<!ENTITY pgbuffercache   SYSTEM "pgbuffercache.sgml">
 <!ENTITY pgcrypto        SYSTEM "pgcrypto.sgml">
-<!ENTITY pgfreespacemap  SYSTEM "pgfreespacemap.sgml">
-<!ENTITY pgrowlocks      SYSTEM "pgrowlocks.sgml">
 <!ENTITY pgstandby       SYSTEM "pgstandby.sgml">
-<!ENTITY pgstatstatements SYSTEM "pgstatstatements.sgml">
-<!ENTITY pgstattuple     SYSTEM "pgstattuple.sgml">
 <!ENTITY pgtestfsync     SYSTEM "pgtestfsync.sgml">
 <!ENTITY pgtrgm          SYSTEM "pgtrgm.sgml">
 <!ENTITY pgupgrade       SYSTEM "pgupgrade.sgml">
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index ac1da22..1a90267 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -257,6 +257,7 @@
   &keywords;
   &features;
   &release;
+  &extensions;
   &contrib;
   &external-projects;
   &sourcerepo;
diff --git a/src/Makefile b/src/Makefile
index a046034..87d6e2c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -24,6 +24,7 @@ SUBDIRS = \
 	bin \
 	pl \
 	makefiles \
+	extension \
 	test/regress
 
 # There are too many interdependencies between the subdirectories, so
diff --git a/src/extension/Makefile b/src/extension/Makefile
new file mode 100644
index 0000000..282f076
--- /dev/null
+++ b/src/extension/Makefile
@@ -0,0 +1,41 @@
+# $PostgreSQL: pgsql/src/extension/Makefile $
+
+subdir = src/extension
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+
+SUBDIRS = \
+		auto_explain    \
+		pageinspect \
+		pg_buffercache \
+		pgrowlocks  \
+		pg_stat_statements \
+		pgstattuple
+
+ifeq ($(with_openssl),yes)
+SUBDIRS += sslinfo
+endif
+
+ifeq ($(with_ossp_uuid),yes)
+SUBDIRS += uuid-ossp
+endif
+
+ifeq ($(with_libxml),yes)
+SUBDIRS += xml2
+endif
+
+# Missing:
+#		start-scripts	\ (does not have a makefile)
+
+
+all install installdirs uninstall distprep clean distclean maintainer-clean:
+	@for dir in $(SUBDIRS); do \
+		$(MAKE) -C $$dir $@ || exit; \
+	done
+
+# We'd like check operations to run all the subtests before failing.
+check installcheck:
+	@CHECKERR=0; for dir in $(SUBDIRS); do \
+		$(MAKE) -C $$dir $@ || CHECKERR=$$?; \
+	done; \
+	exit $$CHECKERR
diff --git a/src/extension/auto_explain/Makefile b/src/extension/auto_explain/Makefile
new file mode 100644
index 0000000..023e59a
--- /dev/null
+++ b/src/extension/auto_explain/Makefile
@@ -0,0 +1,16 @@
+# src/extension/auto_explain/Makefile
+
+MODULE_big = auto_explain
+OBJS = auto_explain.o
+MODULEDIR=extension
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/extension/auto_explain
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/src/extension/extension-global.mk
+endif
diff --git a/src/extension/auto_explain/auto_explain.c b/src/extension/auto_explain/auto_explain.c
new file mode 100644
index 0000000..647f6d0
--- /dev/null
+++ b/src/extension/auto_explain/auto_explain.c
@@ -0,0 +1,304 @@
+/*-------------------------------------------------------------------------
+ *
+ * auto_explain.c
+ *
+ *
+ * Copyright (c) 2008-2011, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/extension/auto_explain/auto_explain.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "commands/explain.h"
+#include "executor/instrument.h"
+#include "utils/guc.h"
+
+PG_MODULE_MAGIC;
+
+/* GUC variables */
+static int	auto_explain_log_min_duration = -1; /* msec or -1 */
+static bool auto_explain_log_analyze = false;
+static bool auto_explain_log_verbose = false;
+static bool auto_explain_log_buffers = false;
+static int	auto_explain_log_format = EXPLAIN_FORMAT_TEXT;
+static bool auto_explain_log_nested_statements = false;
+
+static const struct config_enum_entry format_options[] = {
+	{"text", EXPLAIN_FORMAT_TEXT, false},
+	{"xml", EXPLAIN_FORMAT_XML, false},
+	{"json", EXPLAIN_FORMAT_JSON, false},
+	{"yaml", EXPLAIN_FORMAT_YAML, false},
+	{NULL, 0, false}
+};
+
+/* Current nesting depth of ExecutorRun calls */
+static int	nesting_level = 0;
+
+/* Saved hook values in case of unload */
+static ExecutorStart_hook_type prev_ExecutorStart = NULL;
+static ExecutorRun_hook_type prev_ExecutorRun = NULL;
+static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
+static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
+
+#define auto_explain_enabled() \
+	(auto_explain_log_min_duration >= 0 && \
+	 (nesting_level == 0 || auto_explain_log_nested_statements))
+
+void		_PG_init(void);
+void		_PG_fini(void);
+
+static void explain_ExecutorStart(QueryDesc *queryDesc, int eflags);
+static void explain_ExecutorRun(QueryDesc *queryDesc,
+					ScanDirection direction,
+					long count);
+static void explain_ExecutorFinish(QueryDesc *queryDesc);
+static void explain_ExecutorEnd(QueryDesc *queryDesc);
+
+
+/*
+ * Module load callback
+ */
+void
+_PG_init(void)
+{
+	/* Define custom GUC variables. */
+	DefineCustomIntVariable("auto_explain.log_min_duration",
+		 "Sets the minimum execution time above which plans will be logged.",
+						 "Zero prints all plans. -1 turns this feature off.",
+							&auto_explain_log_min_duration,
+							-1,
+							-1, INT_MAX / 1000,
+							PGC_SUSET,
+							GUC_UNIT_MS,
+							NULL,
+							NULL,
+							NULL);
+
+	DefineCustomBoolVariable("auto_explain.log_analyze",
+							 "Use EXPLAIN ANALYZE for plan logging.",
+							 NULL,
+							 &auto_explain_log_analyze,
+							 false,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	DefineCustomBoolVariable("auto_explain.log_verbose",
+							 "Use EXPLAIN VERBOSE for plan logging.",
+							 NULL,
+							 &auto_explain_log_verbose,
+							 false,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	DefineCustomBoolVariable("auto_explain.log_buffers",
+							 "Log buffers usage.",
+							 NULL,
+							 &auto_explain_log_buffers,
+							 false,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	DefineCustomEnumVariable("auto_explain.log_format",
+							 "EXPLAIN format to be used for plan logging.",
+							 NULL,
+							 &auto_explain_log_format,
+							 EXPLAIN_FORMAT_TEXT,
+							 format_options,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	DefineCustomBoolVariable("auto_explain.log_nested_statements",
+							 "Log nested statements.",
+							 NULL,
+							 &auto_explain_log_nested_statements,
+							 false,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	EmitWarningsOnPlaceholders("auto_explain");
+
+	/* Install hooks. */
+	prev_ExecutorStart = ExecutorStart_hook;
+	ExecutorStart_hook = explain_ExecutorStart;
+	prev_ExecutorRun = ExecutorRun_hook;
+	ExecutorRun_hook = explain_ExecutorRun;
+	prev_ExecutorFinish = ExecutorFinish_hook;
+	ExecutorFinish_hook = explain_ExecutorFinish;
+	prev_ExecutorEnd = ExecutorEnd_hook;
+	ExecutorEnd_hook = explain_ExecutorEnd;
+}
+
+/*
+ * Module unload callback
+ */
+void
+_PG_fini(void)
+{
+	/* Uninstall hooks. */
+	ExecutorStart_hook = prev_ExecutorStart;
+	ExecutorRun_hook = prev_ExecutorRun;
+	ExecutorFinish_hook = prev_ExecutorFinish;
+	ExecutorEnd_hook = prev_ExecutorEnd;
+}
+
+/*
+ * ExecutorStart hook: start up logging if needed
+ */
+static void
+explain_ExecutorStart(QueryDesc *queryDesc, int eflags)
+{
+	if (auto_explain_enabled())
+	{
+		/* Enable per-node instrumentation iff log_analyze is required. */
+		if (auto_explain_log_analyze && (eflags & EXEC_FLAG_EXPLAIN_ONLY) == 0)
+		{
+			queryDesc->instrument_options |= INSTRUMENT_TIMER;
+			if (auto_explain_log_buffers)
+				queryDesc->instrument_options |= INSTRUMENT_BUFFERS;
+		}
+	}
+
+	if (prev_ExecutorStart)
+		prev_ExecutorStart(queryDesc, eflags);
+	else
+		standard_ExecutorStart(queryDesc, eflags);
+
+	if (auto_explain_enabled())
+	{
+		/*
+		 * Set up to track total elapsed time in ExecutorRun.  Make sure the
+		 * space is allocated in the per-query context so it will go away at
+		 * ExecutorEnd.
+		 */
+		if (queryDesc->totaltime == NULL)
+		{
+			MemoryContext oldcxt;
+
+			oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
+			queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL);
+			MemoryContextSwitchTo(oldcxt);
+		}
+	}
+}
+
+/*
+ * ExecutorRun hook: all we need do is track nesting depth
+ */
+static void
+explain_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count)
+{
+	nesting_level++;
+	PG_TRY();
+	{
+		if (prev_ExecutorRun)
+			prev_ExecutorRun(queryDesc, direction, count);
+		else
+			standard_ExecutorRun(queryDesc, direction, count);
+		nesting_level--;
+	}
+	PG_CATCH();
+	{
+		nesting_level--;
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+}
+
+/*
+ * ExecutorFinish hook: all we need do is track nesting depth
+ */
+static void
+explain_ExecutorFinish(QueryDesc *queryDesc)
+{
+	nesting_level++;
+	PG_TRY();
+	{
+		if (prev_ExecutorFinish)
+			prev_ExecutorFinish(queryDesc);
+		else
+			standard_ExecutorFinish(queryDesc);
+		nesting_level--;
+	}
+	PG_CATCH();
+	{
+		nesting_level--;
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+}
+
+/*
+ * ExecutorEnd hook: log results if needed
+ */
+static void
+explain_ExecutorEnd(QueryDesc *queryDesc)
+{
+	if (queryDesc->totaltime && auto_explain_enabled())
+	{
+		double		msec;
+
+		/*
+		 * Make sure stats accumulation is done.  (Note: it's okay if several
+		 * levels of hook all do this.)
+		 */
+		InstrEndLoop(queryDesc->totaltime);
+
+		/* Log plan if duration is exceeded. */
+		msec = queryDesc->totaltime->total * 1000.0;
+		if (msec >= auto_explain_log_min_duration)
+		{
+			ExplainState es;
+
+			ExplainInitState(&es);
+			es.analyze = (queryDesc->instrument_options && auto_explain_log_analyze);
+			es.verbose = auto_explain_log_verbose;
+			es.buffers = (es.analyze && auto_explain_log_buffers);
+			es.format = auto_explain_log_format;
+
+			ExplainBeginOutput(&es);
+			ExplainQueryText(&es, queryDesc);
+			ExplainPrintPlan(&es, queryDesc);
+			ExplainEndOutput(&es);
+
+			/* Remove last line break */
+			if (es.str->len > 0 && es.str->data[es.str->len - 1] == '\n')
+				es.str->data[--es.str->len] = '\0';
+
+			/*
+			 * Note: we rely on the existing logging of context or
+			 * debug_query_string to identify just which statement is being
+			 * reported.  This isn't ideal but trying to do it here would
+			 * often result in duplication.
+			 */
+			ereport(LOG,
+					(errmsg("duration: %.3f ms  plan:\n%s",
+							msec, es.str->data),
+					 errhidestmt(true)));
+
+			pfree(es.str->data);
+		}
+	}
+
+	if (prev_ExecutorEnd)
+		prev_ExecutorEnd(queryDesc);
+	else
+		standard_ExecutorEnd(queryDesc);
+}
diff --git a/src/extension/extension-global.mk b/src/extension/extension-global.mk
new file mode 100644
index 0000000..cc7643b
--- /dev/null
+++ b/src/extension/extension-global.mk
@@ -0,0 +1,5 @@
+# $PostgreSQL: pgsql/extension/extension-global.mk,v 1.10 2005/09/27 17:43:31 tgl Exp $
+
+NO_PGXS = 1
+MODULEDIR=extension
+include $(top_srcdir)/src/makefiles/pgxs.mk
diff --git a/src/extension/pageinspect/Makefile b/src/extension/pageinspect/Makefile
new file mode 100644
index 0000000..c6940b8
--- /dev/null
+++ b/src/extension/pageinspect/Makefile
@@ -0,0 +1,19 @@
+# src/extension/pageinspect/Makefile
+
+MODULE_big	= pageinspect
+OBJS		= rawpage.o heapfuncs.o btreefuncs.o fsmfuncs.o
+MODULEDIR = extension
+
+EXTENSION = pageinspect
+DATA = pageinspect--1.0.sql pageinspect--unpackaged--1.0.sql
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/extension/pageinspect
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/src/extension/extension-global.mk
+endif
diff --git a/src/extension/pageinspect/btreefuncs.c b/src/extension/pageinspect/btreefuncs.c
new file mode 100644
index 0000000..e378560
--- /dev/null
+++ b/src/extension/pageinspect/btreefuncs.c
@@ -0,0 +1,502 @@
+/*
+ * src/extension/pageinspect/btreefuncs.c
+ *
+ *
+ * btreefuncs.c
+ *
+ * Copyright (c) 2006 Satoshi Nagayasu <nagayasus@nttdata.co.jp>
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose, without fee, and without a
+ * written agreement is hereby granted, provided that the above
+ * copyright notice and this paragraph and the following two
+ * paragraphs appear in all copies.
+ *
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
+ * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
+ * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
+ * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "access/nbtree.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "storage/bufmgr.h"
+#include "utils/builtins.h"
+
+
+extern Datum bt_metap(PG_FUNCTION_ARGS);
+extern Datum bt_page_items(PG_FUNCTION_ARGS);
+extern Datum bt_page_stats(PG_FUNCTION_ARGS);
+
+PG_FUNCTION_INFO_V1(bt_metap);
+PG_FUNCTION_INFO_V1(bt_page_items);
+PG_FUNCTION_INFO_V1(bt_page_stats);
+
+#define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
+#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
+
+#define CHECK_PAGE_OFFSET_RANGE(pg, offnum) { \
+		if ( !(FirstOffsetNumber <= (offnum) && \
+						(offnum) <= PageGetMaxOffsetNumber(pg)) ) \
+			 elog(ERROR, "page offset number out of range"); }
+
+/* note: BlockNumber is unsigned, hence can't be negative */
+#define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
+		if ( RelationGetNumberOfBlocks(rel) <= (BlockNumber) (blkno) ) \
+			 elog(ERROR, "block number out of range"); }
+
+/* ------------------------------------------------
+ * structure for single btree page statistics
+ * ------------------------------------------------
+ */
+typedef struct BTPageStat
+{
+	uint32		blkno;
+	uint32		live_items;
+	uint32		dead_items;
+	uint32		page_size;
+	uint32		max_avail;
+	uint32		free_size;
+	uint32		avg_item_size;
+	char		type;
+
+	/* opaque data */
+	BlockNumber btpo_prev;
+	BlockNumber btpo_next;
+	union
+	{
+		uint32		level;
+		TransactionId xact;
+	}			btpo;
+	uint16		btpo_flags;
+	BTCycleId	btpo_cycleid;
+} BTPageStat;
+
+
+/* -------------------------------------------------
+ * GetBTPageStatistics()
+ *
+ * Collect statistics of single b-tree page
+ * -------------------------------------------------
+ */
+static void
+GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat *stat)
+{
+	Page		page = BufferGetPage(buffer);
+	PageHeader	phdr = (PageHeader) page;
+	OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
+	BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+	int			item_size = 0;
+	int			off;
+
+	stat->blkno = blkno;
+
+	stat->max_avail = BLCKSZ - (BLCKSZ - phdr->pd_special + SizeOfPageHeaderData);
+
+	stat->dead_items = stat->live_items = 0;
+
+	stat->page_size = PageGetPageSize(page);
+
+	/* page type (flags) */
+	if (P_ISDELETED(opaque))
+	{
+		stat->type = 'd';
+		stat->btpo.xact = opaque->btpo.xact;
+		return;
+	}
+	else if (P_IGNORE(opaque))
+		stat->type = 'e';
+	else if (P_ISLEAF(opaque))
+		stat->type = 'l';
+	else if (P_ISROOT(opaque))
+		stat->type = 'r';
+	else
+		stat->type = 'i';
+
+	/* btpage opaque data */
+	stat->btpo_prev = opaque->btpo_prev;
+	stat->btpo_next = opaque->btpo_next;
+	stat->btpo.level = opaque->btpo.level;
+	stat->btpo_flags = opaque->btpo_flags;
+	stat->btpo_cycleid = opaque->btpo_cycleid;
+
+	/* count live and dead tuples, and free space */
+	for (off = FirstOffsetNumber; off <= maxoff; off++)
+	{
+		IndexTuple	itup;
+
+		ItemId		id = PageGetItemId(page, off);
+
+		itup = (IndexTuple) PageGetItem(page, id);
+
+		item_size += IndexTupleSize(itup);
+
+		if (!ItemIdIsDead(id))
+			stat->live_items++;
+		else
+			stat->dead_items++;
+	}
+	stat->free_size = PageGetFreeSpace(page);
+
+	if ((stat->live_items + stat->dead_items) > 0)
+		stat->avg_item_size = item_size / (stat->live_items + stat->dead_items);
+	else
+		stat->avg_item_size = 0;
+}
+
+/* -----------------------------------------------
+ * bt_page()
+ *
+ * Usage: SELECT * FROM bt_page('t1_pkey', 1);
+ * -----------------------------------------------
+ */
+Datum
+bt_page_stats(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	uint32		blkno = PG_GETARG_UINT32(1);
+	Buffer		buffer;
+	Relation	rel;
+	RangeVar   *relrv;
+	Datum		result;
+	HeapTuple	tuple;
+	TupleDesc	tupleDesc;
+	int			j;
+	char	   *values[11];
+	BTPageStat	stat;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pageinspect functions"))));
+
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	if (!IS_INDEX(rel) || !IS_BTREE(rel))
+		elog(ERROR, "relation \"%s\" is not a btree index",
+			 RelationGetRelationName(rel));
+
+	/*
+	 * Reject attempts to read non-local temporary relations; we would be
+	 * likely to get wrong data since we have no visibility into the owning
+	 * session's local buffers.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot access temporary tables of other sessions")));
+
+	if (blkno == 0)
+		elog(ERROR, "block 0 is a meta page");
+
+	CHECK_RELATION_BLOCK_RANGE(rel, blkno);
+
+	buffer = ReadBuffer(rel, blkno);
+
+	/* keep compiler quiet */
+	stat.btpo_prev = stat.btpo_next = InvalidBlockNumber;
+	stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;
+
+	GetBTPageStatistics(blkno, buffer, &stat);
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	j = 0;
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.blkno);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%c", stat.type);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.live_items);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.dead_items);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.avg_item_size);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.page_size);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.free_size);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.btpo_prev);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.btpo_next);
+	values[j] = palloc(32);
+	if (stat.type == 'd')
+		snprintf(values[j++], 32, "%d", stat.btpo.xact);
+	else
+		snprintf(values[j++], 32, "%d", stat.btpo.level);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", stat.btpo_flags);
+
+	tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
+								   values);
+
+	result = HeapTupleGetDatum(tuple);
+
+	ReleaseBuffer(buffer);
+
+	relation_close(rel, AccessShareLock);
+
+	PG_RETURN_DATUM(result);
+}
+
+/*-------------------------------------------------------
+ * bt_page_items()
+ *
+ * Get IndexTupleData set in a btree page
+ *
+ * Usage: SELECT * FROM bt_page_items('t1_pkey', 1);
+ *-------------------------------------------------------
+ */
+
+/*
+ * cross-call data structure for SRF
+ */
+struct user_args
+{
+	Page		page;
+	OffsetNumber offset;
+};
+
+Datum
+bt_page_items(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	uint32		blkno = PG_GETARG_UINT32(1);
+	Datum		result;
+	char	   *values[6];
+	HeapTuple	tuple;
+	FuncCallContext *fctx;
+	MemoryContext mctx;
+	struct user_args *uargs;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pageinspect functions"))));
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		RangeVar   *relrv;
+		Relation	rel;
+		Buffer		buffer;
+		BTPageOpaque opaque;
+		TupleDesc	tupleDesc;
+
+		fctx = SRF_FIRSTCALL_INIT();
+
+		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+		rel = relation_openrv(relrv, AccessShareLock);
+
+		if (!IS_INDEX(rel) || !IS_BTREE(rel))
+			elog(ERROR, "relation \"%s\" is not a btree index",
+				 RelationGetRelationName(rel));
+
+		/*
+		 * Reject attempts to read non-local temporary relations; we would be
+		 * likely to get wrong data since we have no visibility into the
+		 * owning session's local buffers.
+		 */
+		if (RELATION_IS_OTHER_TEMP(rel))
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("cannot access temporary tables of other sessions")));
+
+		if (blkno == 0)
+			elog(ERROR, "block 0 is a meta page");
+
+		CHECK_RELATION_BLOCK_RANGE(rel, blkno);
+
+		buffer = ReadBuffer(rel, blkno);
+
+		/*
+		 * We copy the page into local storage to avoid holding pin on the
+		 * buffer longer than we must, and possibly failing to release it at
+		 * all if the calling query doesn't fetch all rows.
+		 */
+		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
+
+		uargs = palloc(sizeof(struct user_args));
+
+		uargs->page = palloc(BLCKSZ);
+		memcpy(uargs->page, BufferGetPage(buffer), BLCKSZ);
+
+		ReleaseBuffer(buffer);
+		relation_close(rel, AccessShareLock);
+
+		uargs->offset = FirstOffsetNumber;
+
+		opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page);
+
+		if (P_ISDELETED(opaque))
+			elog(NOTICE, "page is deleted");
+
+		fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
+
+		/* Build a tuple descriptor for our result type */
+		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+			elog(ERROR, "return type must be a row type");
+
+		fctx->attinmeta = TupleDescGetAttInMetadata(tupleDesc);
+
+		fctx->user_fctx = uargs;
+
+		MemoryContextSwitchTo(mctx);
+	}
+
+	fctx = SRF_PERCALL_SETUP();
+	uargs = fctx->user_fctx;
+
+	if (fctx->call_cntr < fctx->max_calls)
+	{
+		ItemId		id;
+		IndexTuple	itup;
+		int			j;
+		int			off;
+		int			dlen;
+		char	   *dump;
+		char	   *ptr;
+
+		id = PageGetItemId(uargs->page, uargs->offset);
+
+		if (!ItemIdIsValid(id))
+			elog(ERROR, "invalid ItemId");
+
+		itup = (IndexTuple) PageGetItem(uargs->page, id);
+
+		j = 0;
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%d", uargs->offset);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "(%u,%u)",
+				 BlockIdGetBlockNumber(&(itup->t_tid.ip_blkid)),
+				 itup->t_tid.ip_posid);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%d", (int) IndexTupleSize(itup));
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%c", IndexTupleHasNulls(itup) ? 't' : 'f');
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');
+
+		ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
+		dlen = IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
+		dump = palloc0(dlen * 3 + 1);
+		values[j] = dump;
+		for (off = 0; off < dlen; off++)
+		{
+			if (off > 0)
+				*dump++ = ' ';
+			sprintf(dump, "%02x", *(ptr + off) & 0xff);
+			dump += 2;
+		}
+
+		tuple = BuildTupleFromCStrings(fctx->attinmeta, values);
+		result = HeapTupleGetDatum(tuple);
+
+		uargs->offset = uargs->offset + 1;
+
+		SRF_RETURN_NEXT(fctx, result);
+	}
+	else
+	{
+		pfree(uargs->page);
+		pfree(uargs);
+		SRF_RETURN_DONE(fctx);
+	}
+}
+
+
+/* ------------------------------------------------
+ * bt_metap()
+ *
+ * Get a btree's meta-page information
+ *
+ * Usage: SELECT * FROM bt_metap('t1_pkey')
+ * ------------------------------------------------
+ */
+Datum
+bt_metap(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	Datum		result;
+	Relation	rel;
+	RangeVar   *relrv;
+	BTMetaPageData *metad;
+	TupleDesc	tupleDesc;
+	int			j;
+	char	   *values[6];
+	Buffer		buffer;
+	Page		page;
+	HeapTuple	tuple;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pageinspect functions"))));
+
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	if (!IS_INDEX(rel) || !IS_BTREE(rel))
+		elog(ERROR, "relation \"%s\" is not a btree index",
+			 RelationGetRelationName(rel));
+
+	/*
+	 * Reject attempts to read non-local temporary relations; we would be
+	 * likely to get wrong data since we have no visibility into the owning
+	 * session's local buffers.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot access temporary tables of other sessions")));
+
+	buffer = ReadBuffer(rel, 0);
+	page = BufferGetPage(buffer);
+	metad = BTPageGetMeta(page);
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	j = 0;
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", metad->btm_magic);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", metad->btm_version);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", metad->btm_root);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", metad->btm_level);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", metad->btm_fastroot);
+	values[j] = palloc(32);
+	snprintf(values[j++], 32, "%d", metad->btm_fastlevel);
+
+	tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
+								   values);
+
+	result = HeapTupleGetDatum(tuple);
+
+	ReleaseBuffer(buffer);
+
+	relation_close(rel, AccessShareLock);
+
+	PG_RETURN_DATUM(result);
+}
diff --git a/src/extension/pageinspect/fsmfuncs.c b/src/extension/pageinspect/fsmfuncs.c
new file mode 100644
index 0000000..45b2b9d
--- /dev/null
+++ b/src/extension/pageinspect/fsmfuncs.c
@@ -0,0 +1,59 @@
+/*-------------------------------------------------------------------------
+ *
+ * fsmfuncs.c
+ *	  Functions to investigate FSM pages
+ *
+ * These functions are restricted to superusers for the fear of introducing
+ * security holes if the input checking isn't as water-tight as it should.
+ * You'd need to be superuser to obtain a raw page image anyway, so
+ * there's hardly any use case for using these without superuser-rights
+ * anyway.
+ *
+ * Copyright (c) 2007-2011, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/extension/pageinspect/fsmfuncs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "lib/stringinfo.h"
+#include "storage/fsm_internals.h"
+#include "utils/builtins.h"
+#include "miscadmin.h"
+#include "funcapi.h"
+
+Datum		fsm_page_contents(PG_FUNCTION_ARGS);
+
+/*
+ * Dumps the contents of a FSM page.
+ */
+PG_FUNCTION_INFO_V1(fsm_page_contents);
+
+Datum
+fsm_page_contents(PG_FUNCTION_ARGS)
+{
+	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
+	StringInfoData sinfo;
+	FSMPage		fsmpage;
+	int			i;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use raw page functions"))));
+
+	fsmpage = (FSMPage) PageGetContents(VARDATA(raw_page));
+
+	initStringInfo(&sinfo);
+
+	for (i = 0; i < NodesPerPage; i++)
+	{
+		if (fsmpage->fp_nodes[i] != 0)
+			appendStringInfo(&sinfo, "%d: %d\n", i, fsmpage->fp_nodes[i]);
+	}
+	appendStringInfo(&sinfo, "fp_next_slot: %d\n", fsmpage->fp_next_slot);
+
+	PG_RETURN_TEXT_P(cstring_to_text(sinfo.data));
+}
diff --git a/src/extension/pageinspect/heapfuncs.c b/src/extension/pageinspect/heapfuncs.c
new file mode 100644
index 0000000..a9f95b4
--- /dev/null
+++ b/src/extension/pageinspect/heapfuncs.c
@@ -0,0 +1,230 @@
+/*-------------------------------------------------------------------------
+ *
+ * heapfuncs.c
+ *	  Functions to investigate heap pages
+ *
+ * We check the input to these functions for corrupt pointers etc. that
+ * might cause crashes, but at the same time we try to print out as much
+ * information as possible, even if it's nonsense. That's because if a
+ * page is corrupt, we don't know why and how exactly it is corrupt, so we
+ * let the user judge it.
+ *
+ * These functions are restricted to superusers for the fear of introducing
+ * security holes if the input checking isn't as water-tight as it should be.
+ * You'd need to be superuser to obtain a raw page image anyway, so
+ * there's hardly any use case for using these without superuser-rights
+ * anyway.
+ *
+ * Copyright (c) 2007-2011, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/extension/pageinspect/heapfuncs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "fmgr.h"
+#include "funcapi.h"
+#include "access/heapam.h"
+#include "access/transam.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "utils/builtins.h"
+#include "miscadmin.h"
+
+Datum		heap_page_items(PG_FUNCTION_ARGS);
+
+
+/*
+ * bits_to_text
+ *
+ * Converts a bits8-array of 'len' bits to a human-readable
+ * c-string representation.
+ */
+static char *
+bits_to_text(bits8 *bits, int len)
+{
+	int			i;
+	char	   *str;
+
+	str = palloc(len + 1);
+
+	for (i = 0; i < len; i++)
+		str[i] = (bits[(i / 8)] & (1 << (i % 8))) ? '1' : '0';
+
+	str[i] = '\0';
+
+	return str;
+}
+
+
+/*
+ * heap_page_items
+ *
+ * Allows inspection of line pointers and tuple headers of a heap page.
+ */
+PG_FUNCTION_INFO_V1(heap_page_items);
+
+typedef struct heap_page_items_state
+{
+	TupleDesc	tupd;
+	Page		page;
+	uint16		offset;
+} heap_page_items_state;
+
+Datum
+heap_page_items(PG_FUNCTION_ARGS)
+{
+	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
+	heap_page_items_state *inter_call_data = NULL;
+	FuncCallContext *fctx;
+	int			raw_page_size;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use raw page functions"))));
+
+	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		TupleDesc	tupdesc;
+		MemoryContext mctx;
+
+		if (raw_page_size < SizeOfPageHeaderData)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				  errmsg("input page too small (%d bytes)", raw_page_size)));
+
+		fctx = SRF_FIRSTCALL_INIT();
+		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
+
+		inter_call_data = palloc(sizeof(heap_page_items_state));
+
+		/* Build a tuple descriptor for our result type */
+		if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+			elog(ERROR, "return type must be a row type");
+
+		inter_call_data->tupd = tupdesc;
+
+		inter_call_data->offset = FirstOffsetNumber;
+		inter_call_data->page = VARDATA(raw_page);
+
+		fctx->max_calls = PageGetMaxOffsetNumber(inter_call_data->page);
+		fctx->user_fctx = inter_call_data;
+
+		MemoryContextSwitchTo(mctx);
+	}
+
+	fctx = SRF_PERCALL_SETUP();
+	inter_call_data = fctx->user_fctx;
+
+	if (fctx->call_cntr < fctx->max_calls)
+	{
+		Page		page = inter_call_data->page;
+		HeapTuple	resultTuple;
+		Datum		result;
+		ItemId		id;
+		Datum		values[13];
+		bool		nulls[13];
+		uint16		lp_offset;
+		uint16		lp_flags;
+		uint16		lp_len;
+
+		memset(nulls, 0, sizeof(nulls));
+
+		/* Extract information from the line pointer */
+
+		id = PageGetItemId(page, inter_call_data->offset);
+
+		lp_offset = ItemIdGetOffset(id);
+		lp_flags = ItemIdGetFlags(id);
+		lp_len = ItemIdGetLength(id);
+
+		values[0] = UInt16GetDatum(inter_call_data->offset);
+		values[1] = UInt16GetDatum(lp_offset);
+		values[2] = UInt16GetDatum(lp_flags);
+		values[3] = UInt16GetDatum(lp_len);
+
+		/*
+		 * We do just enough validity checking to make sure we don't reference
+		 * data outside the page passed to us. The page could be corrupt in
+		 * many other ways, but at least we won't crash.
+		 */
+		if (ItemIdHasStorage(id) &&
+			lp_len >= sizeof(HeapTupleHeader) &&
+			lp_offset == MAXALIGN(lp_offset) &&
+			lp_offset + lp_len <= raw_page_size)
+		{
+			HeapTupleHeader tuphdr;
+			int			bits_len;
+
+			/* Extract information from the tuple header */
+
+			tuphdr = (HeapTupleHeader) PageGetItem(page, id);
+
+			values[4] = UInt32GetDatum(HeapTupleHeaderGetXmin(tuphdr));
+			values[5] = UInt32GetDatum(HeapTupleHeaderGetXmax(tuphdr));
+			values[6] = UInt32GetDatum(HeapTupleHeaderGetRawCommandId(tuphdr)); /* shared with xvac */
+			values[7] = PointerGetDatum(&tuphdr->t_ctid);
+			values[8] = UInt32GetDatum(tuphdr->t_infomask2);
+			values[9] = UInt32GetDatum(tuphdr->t_infomask);
+			values[10] = UInt8GetDatum(tuphdr->t_hoff);
+
+			/*
+			 * We already checked that the item as is completely within the
+			 * raw page passed to us, with the length given in the line
+			 * pointer.. Let's check that t_hoff doesn't point over lp_len,
+			 * before using it to access t_bits and oid.
+			 */
+			if (tuphdr->t_hoff >= sizeof(HeapTupleHeader) &&
+				tuphdr->t_hoff <= lp_len)
+			{
+				if (tuphdr->t_infomask & HEAP_HASNULL)
+				{
+					bits_len = tuphdr->t_hoff -
+						(((char *) tuphdr->t_bits) -((char *) tuphdr));
+
+					values[11] = CStringGetTextDatum(
+								 bits_to_text(tuphdr->t_bits, bits_len * 8));
+				}
+				else
+					nulls[11] = true;
+
+				if (tuphdr->t_infomask & HEAP_HASOID)
+					values[12] = HeapTupleHeaderGetOid(tuphdr);
+				else
+					nulls[12] = true;
+			}
+			else
+			{
+				nulls[11] = true;
+				nulls[12] = true;
+			}
+		}
+		else
+		{
+			/*
+			 * The line pointer is not used, or it's invalid. Set the rest of
+			 * the fields to NULL
+			 */
+			int			i;
+
+			for (i = 4; i <= 12; i++)
+				nulls[i] = true;
+		}
+
+		/* Build and return the result tuple. */
+		resultTuple = heap_form_tuple(inter_call_data->tupd, values, nulls);
+		result = HeapTupleGetDatum(resultTuple);
+
+		inter_call_data->offset++;
+
+		SRF_RETURN_NEXT(fctx, result);
+	}
+	else
+		SRF_RETURN_DONE(fctx);
+}
diff --git a/src/extension/pageinspect/pageinspect--1.0.sql b/src/extension/pageinspect/pageinspect--1.0.sql
new file mode 100644
index 0000000..cadcb4a
--- /dev/null
+++ b/src/extension/pageinspect/pageinspect--1.0.sql
@@ -0,0 +1,104 @@
+/* src/extension/pageinspect/pageinspect--1.0.sql */
+
+--
+-- get_raw_page()
+--
+CREATE FUNCTION get_raw_page(text, int4)
+RETURNS bytea
+AS 'MODULE_PATHNAME', 'get_raw_page'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION get_raw_page(text, text, int4)
+RETURNS bytea
+AS 'MODULE_PATHNAME', 'get_raw_page_fork'
+LANGUAGE C STRICT;
+
+--
+-- page_header()
+--
+CREATE FUNCTION page_header(IN page bytea,
+    OUT lsn text,
+    OUT tli smallint,
+    OUT flags smallint,
+    OUT lower smallint,
+    OUT upper smallint,
+    OUT special smallint,
+    OUT pagesize smallint,
+    OUT version smallint,
+    OUT prune_xid xid)
+AS 'MODULE_PATHNAME', 'page_header'
+LANGUAGE C STRICT;
+
+--
+-- heap_page_items()
+--
+CREATE FUNCTION heap_page_items(IN page bytea,
+    OUT lp smallint,
+    OUT lp_off smallint,
+    OUT lp_flags smallint,
+    OUT lp_len smallint,
+    OUT t_xmin xid,
+    OUT t_xmax xid,
+    OUT t_field3 int4,
+    OUT t_ctid tid,
+    OUT t_infomask2 integer,
+    OUT t_infomask integer,
+    OUT t_hoff smallint,
+    OUT t_bits text,
+    OUT t_oid oid)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'heap_page_items'
+LANGUAGE C STRICT;
+
+--
+-- bt_metap()
+--
+CREATE FUNCTION bt_metap(IN relname text,
+    OUT magic int4,
+    OUT version int4,
+    OUT root int4,
+    OUT level int4,
+    OUT fastroot int4,
+    OUT fastlevel int4)
+AS 'MODULE_PATHNAME', 'bt_metap'
+LANGUAGE C STRICT;
+
+--
+-- bt_page_stats()
+--
+CREATE FUNCTION bt_page_stats(IN relname text, IN blkno int4,
+    OUT blkno int4,
+    OUT type "char",
+    OUT live_items int4,
+    OUT dead_items int4,
+    OUT avg_item_size int4,
+    OUT page_size int4,
+    OUT free_size int4,
+    OUT btpo_prev int4,
+    OUT btpo_next int4,
+    OUT btpo int4,
+    OUT btpo_flags int4)
+AS 'MODULE_PATHNAME', 'bt_page_stats'
+LANGUAGE C STRICT;
+
+--
+-- bt_page_items()
+--
+CREATE FUNCTION bt_page_items(IN relname text, IN blkno int4,
+    OUT itemoffset smallint,
+    OUT ctid tid,
+    OUT itemlen smallint,
+    OUT nulls bool,
+    OUT vars bool,
+    OUT data text)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'bt_page_items'
+LANGUAGE C STRICT;
+
+--
+-- fsm_page_contents()
+--
+CREATE FUNCTION fsm_page_contents(IN page bytea)
+RETURNS text
+AS 'MODULE_PATHNAME', 'fsm_page_contents'
+LANGUAGE C STRICT;
diff --git a/src/extension/pageinspect/pageinspect--unpackaged--1.0.sql b/src/extension/pageinspect/pageinspect--unpackaged--1.0.sql
new file mode 100644
index 0000000..9e9d8cf
--- /dev/null
+++ b/src/extension/pageinspect/pageinspect--unpackaged--1.0.sql
@@ -0,0 +1,28 @@
+/* src/extension/pageinspect/pageinspect--unpackaged--1.0.sql */
+
+DROP FUNCTION heap_page_items(bytea);
+CREATE FUNCTION heap_page_items(IN page bytea,
+	OUT lp smallint,
+	OUT lp_off smallint,
+	OUT lp_flags smallint,
+	OUT lp_len smallint,
+	OUT t_xmin xid,
+	OUT t_xmax xid,
+	OUT t_field3 int4,
+	OUT t_ctid tid,
+	OUT t_infomask2 integer,
+	OUT t_infomask integer,
+	OUT t_hoff smallint,
+	OUT t_bits text,
+	OUT t_oid oid)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'heap_page_items'
+LANGUAGE C STRICT;
+
+ALTER EXTENSION pageinspect ADD function get_raw_page(text,integer);
+ALTER EXTENSION pageinspect ADD function get_raw_page(text,text,integer);
+ALTER EXTENSION pageinspect ADD function page_header(bytea);
+ALTER EXTENSION pageinspect ADD function bt_metap(text);
+ALTER EXTENSION pageinspect ADD function bt_page_stats(text,integer);
+ALTER EXTENSION pageinspect ADD function bt_page_items(text,integer);
+ALTER EXTENSION pageinspect ADD function fsm_page_contents(bytea);
diff --git a/src/extension/pageinspect/pageinspect.control b/src/extension/pageinspect/pageinspect.control
new file mode 100644
index 0000000..f9da0e8
--- /dev/null
+++ b/src/extension/pageinspect/pageinspect.control
@@ -0,0 +1,5 @@
+# pageinspect extension
+comment = 'inspect the contents of database pages at a low level'
+default_version = '1.0'
+module_pathname = '$libdir/pageinspect'
+relocatable = true
diff --git a/src/extension/pageinspect/rawpage.c b/src/extension/pageinspect/rawpage.c
new file mode 100644
index 0000000..87a029f
--- /dev/null
+++ b/src/extension/pageinspect/rawpage.c
@@ -0,0 +1,232 @@
+/*-------------------------------------------------------------------------
+ *
+ * rawpage.c
+ *	  Functions to extract a raw page as bytea and inspect it
+ *
+ * Access-method specific inspection functions are in separate files.
+ *
+ * Copyright (c) 2007-2011, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/extension/pageinspect/rawpage.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "access/transam.h"
+#include "catalog/catalog.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "fmgr.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "storage/bufmgr.h"
+#include "utils/builtins.h"
+
+PG_MODULE_MAGIC;
+
+Datum		get_raw_page(PG_FUNCTION_ARGS);
+Datum		get_raw_page_fork(PG_FUNCTION_ARGS);
+Datum		page_header(PG_FUNCTION_ARGS);
+
+static bytea *get_raw_page_internal(text *relname, ForkNumber forknum,
+					  BlockNumber blkno);
+
+
+/*
+ * get_raw_page
+ *
+ * Returns a copy of a page from shared buffers as a bytea
+ */
+PG_FUNCTION_INFO_V1(get_raw_page);
+
+Datum
+get_raw_page(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	uint32		blkno = PG_GETARG_UINT32(1);
+	bytea	   *raw_page;
+
+	/*
+	 * We don't normally bother to check the number of arguments to a C
+	 * function, but here it's needed for safety because early 8.4 beta
+	 * releases mistakenly redefined get_raw_page() as taking three arguments.
+	 */
+	if (PG_NARGS() != 2)
+		ereport(ERROR,
+				(errmsg("wrong number of arguments to get_raw_page()"),
+				 errhint("Run the updated pageinspect.sql script.")));
+
+	raw_page = get_raw_page_internal(relname, MAIN_FORKNUM, blkno);
+
+	PG_RETURN_BYTEA_P(raw_page);
+}
+
+/*
+ * get_raw_page_fork
+ *
+ * Same, for any fork
+ */
+PG_FUNCTION_INFO_V1(get_raw_page_fork);
+
+Datum
+get_raw_page_fork(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	text	   *forkname = PG_GETARG_TEXT_P(1);
+	uint32		blkno = PG_GETARG_UINT32(2);
+	bytea	   *raw_page;
+	ForkNumber	forknum;
+
+	forknum = forkname_to_number(text_to_cstring(forkname));
+
+	raw_page = get_raw_page_internal(relname, forknum, blkno);
+
+	PG_RETURN_BYTEA_P(raw_page);
+}
+
+/*
+ * workhorse
+ */
+static bytea *
+get_raw_page_internal(text *relname, ForkNumber forknum, BlockNumber blkno)
+{
+	bytea	   *raw_page;
+	RangeVar   *relrv;
+	Relation	rel;
+	char	   *raw_page_data;
+	Buffer		buf;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use raw functions"))));
+
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	/* Check that this relation has storage */
+	if (rel->rd_rel->relkind == RELKIND_VIEW)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot get raw page from view \"%s\"",
+						RelationGetRelationName(rel))));
+	if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot get raw page from composite type \"%s\"",
+						RelationGetRelationName(rel))));
+	if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot get raw page from foreign table \"%s\"",
+						RelationGetRelationName(rel))));
+
+	/*
+	 * Reject attempts to read non-local temporary relations; we would be
+	 * likely to get wrong data since we have no visibility into the owning
+	 * session's local buffers.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot access temporary tables of other sessions")));
+
+	if (blkno >= RelationGetNumberOfBlocks(rel))
+		elog(ERROR, "block number %u is out of range for relation \"%s\"",
+			 blkno, RelationGetRelationName(rel));
+
+	/* Initialize buffer to copy to */
+	raw_page = (bytea *) palloc(BLCKSZ + VARHDRSZ);
+	SET_VARSIZE(raw_page, BLCKSZ + VARHDRSZ);
+	raw_page_data = VARDATA(raw_page);
+
+	/* Take a verbatim copy of the page */
+
+	buf = ReadBufferExtended(rel, forknum, blkno, RBM_NORMAL, NULL);
+	LockBuffer(buf, BUFFER_LOCK_SHARE);
+
+	memcpy(raw_page_data, BufferGetPage(buf), BLCKSZ);
+
+	LockBuffer(buf, BUFFER_LOCK_UNLOCK);
+	ReleaseBuffer(buf);
+
+	relation_close(rel, AccessShareLock);
+
+	return raw_page;
+}
+
+/*
+ * page_header
+ *
+ * Allows inspection of page header fields of a raw page
+ */
+
+PG_FUNCTION_INFO_V1(page_header);
+
+Datum
+page_header(PG_FUNCTION_ARGS)
+{
+	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
+	int			raw_page_size;
+
+	TupleDesc	tupdesc;
+
+	Datum		result;
+	HeapTuple	tuple;
+	Datum		values[9];
+	bool		nulls[9];
+
+	PageHeader	page;
+	XLogRecPtr	lsn;
+	char		lsnchar[64];
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use raw page functions"))));
+
+	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
+
+	/*
+	 * Check that enough data was supplied, so that we don't try to access
+	 * fields outside the supplied buffer.
+	 */
+	if (raw_page_size < sizeof(PageHeaderData))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("input page too small (%d bytes)", raw_page_size)));
+
+	page = (PageHeader) VARDATA(raw_page);
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	/* Extract information from the page header */
+
+	lsn = PageGetLSN(page);
+	snprintf(lsnchar, sizeof(lsnchar), "%X/%X", lsn.xlogid, lsn.xrecoff);
+
+	values[0] = CStringGetTextDatum(lsnchar);
+	values[1] = UInt16GetDatum(PageGetTLI(page));
+	values[2] = UInt16GetDatum(page->pd_flags);
+	values[3] = UInt16GetDatum(page->pd_lower);
+	values[4] = UInt16GetDatum(page->pd_upper);
+	values[5] = UInt16GetDatum(page->pd_special);
+	values[6] = UInt16GetDatum(PageGetPageSize(page));
+	values[7] = UInt16GetDatum(PageGetPageLayoutVersion(page));
+	values[8] = TransactionIdGetDatum(page->pd_prune_xid);
+
+	/* Build and return the tuple. */
+
+	memset(nulls, 0, sizeof(nulls));
+
+	tuple = heap_form_tuple(tupdesc, values, nulls);
+	result = HeapTupleGetDatum(tuple);
+
+	PG_RETURN_DATUM(result);
+}
diff --git a/src/extension/pg_buffercache/Makefile b/src/extension/pg_buffercache/Makefile
new file mode 100644
index 0000000..e361592
--- /dev/null
+++ b/src/extension/pg_buffercache/Makefile
@@ -0,0 +1,19 @@
+# src/extension/pg_buffercache/Makefile
+
+MODULE_big = pg_buffercache
+OBJS = pg_buffercache_pages.o
+MODULEDIR = extension
+
+EXTENSION = pg_buffercache
+DATA = pg_buffercache--1.0.sql pg_buffercache--unpackaged--1.0.sql
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/extension/pg_buffercache
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/src/extension/extension-global.mk
+endif
diff --git a/src/extension/pg_buffercache/pg_buffercache--1.0.sql b/src/extension/pg_buffercache/pg_buffercache--1.0.sql
new file mode 100644
index 0000000..ceca6ae
--- /dev/null
+++ b/src/extension/pg_buffercache/pg_buffercache--1.0.sql
@@ -0,0 +1,17 @@
+/* src/extension/pg_buffercache/pg_buffercache--1.0.sql */
+
+-- Register the function.
+CREATE FUNCTION pg_buffercache_pages()
+RETURNS SETOF RECORD
+AS 'MODULE_PATHNAME', 'pg_buffercache_pages'
+LANGUAGE C;
+
+-- Create a view for convenient access.
+CREATE VIEW pg_buffercache AS
+	SELECT P.* FROM pg_buffercache_pages() AS P
+	(bufferid integer, relfilenode oid, reltablespace oid, reldatabase oid,
+	 relforknumber int2, relblocknumber int8, isdirty bool, usagecount int2);
+
+-- Don't want these to be available to public.
+REVOKE ALL ON FUNCTION pg_buffercache_pages() FROM PUBLIC;
+REVOKE ALL ON pg_buffercache FROM PUBLIC;
diff --git a/src/extension/pg_buffercache/pg_buffercache--unpackaged--1.0.sql b/src/extension/pg_buffercache/pg_buffercache--unpackaged--1.0.sql
new file mode 100644
index 0000000..0cfa317
--- /dev/null
+++ b/src/extension/pg_buffercache/pg_buffercache--unpackaged--1.0.sql
@@ -0,0 +1,4 @@
+/* src/extension/pg_buffercache/pg_buffercache--unpackaged--1.0.sql */
+
+ALTER EXTENSION pg_buffercache ADD function pg_buffercache_pages();
+ALTER EXTENSION pg_buffercache ADD view pg_buffercache;
diff --git a/src/extension/pg_buffercache/pg_buffercache.control b/src/extension/pg_buffercache/pg_buffercache.control
new file mode 100644
index 0000000..709513c
--- /dev/null
+++ b/src/extension/pg_buffercache/pg_buffercache.control
@@ -0,0 +1,5 @@
+# pg_buffercache extension
+comment = 'examine the shared buffer cache'
+default_version = '1.0'
+module_pathname = '$libdir/pg_buffercache'
+relocatable = true
diff --git a/src/extension/pg_buffercache/pg_buffercache_pages.c b/src/extension/pg_buffercache/pg_buffercache_pages.c
new file mode 100644
index 0000000..a44610f
--- /dev/null
+++ b/src/extension/pg_buffercache/pg_buffercache_pages.c
@@ -0,0 +1,219 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_buffercache_pages.c
+ *	  display some contents of the buffer cache
+ *
+ *	  src/extension/pg_buffercache/pg_buffercache_pages.c
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+#include "storage/buf_internals.h"
+#include "storage/bufmgr.h"
+#include "utils/relcache.h"
+
+
+#define NUM_BUFFERCACHE_PAGES_ELEM	8
+
+PG_MODULE_MAGIC;
+
+Datum		pg_buffercache_pages(PG_FUNCTION_ARGS);
+
+
+/*
+ * Record structure holding the to be exposed cache data.
+ */
+typedef struct
+{
+	uint32		bufferid;
+	Oid			relfilenode;
+	Oid			reltablespace;
+	Oid			reldatabase;
+	ForkNumber	forknum;
+	BlockNumber blocknum;
+	bool		isvalid;
+	bool		isdirty;
+	uint16		usagecount;
+} BufferCachePagesRec;
+
+
+/*
+ * Function context for data persisting over repeated calls.
+ */
+typedef struct
+{
+	TupleDesc	tupdesc;
+	BufferCachePagesRec *record;
+} BufferCachePagesContext;
+
+
+/*
+ * Function returning data from the shared buffer cache - buffer number,
+ * relation node/tablespace/database/blocknum and dirty indicator.
+ */
+PG_FUNCTION_INFO_V1(pg_buffercache_pages);
+
+Datum
+pg_buffercache_pages(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	Datum		result;
+	MemoryContext oldcontext;
+	BufferCachePagesContext *fctx;		/* User function context. */
+	TupleDesc	tupledesc;
+	HeapTuple	tuple;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		int			i;
+		volatile BufferDesc *bufHdr;
+
+		funcctx = SRF_FIRSTCALL_INIT();
+
+		/* Switch context when allocating stuff to be used in later calls */
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		/* Create a user function context for cross-call persistence */
+		fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
+
+		/* Construct a tuple descriptor for the result rows. */
+		tupledesc = CreateTemplateTupleDesc(NUM_BUFFERCACHE_PAGES_ELEM, false);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
+						   INT4OID, -1, 0);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 2, "relfilenode",
+						   OIDOID, -1, 0);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 3, "reltablespace",
+						   OIDOID, -1, 0);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 4, "reldatabase",
+						   OIDOID, -1, 0);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 5, "relforknumber",
+						   INT2OID, -1, 0);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 6, "relblocknumber",
+						   INT8OID, -1, 0);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 7, "isdirty",
+						   BOOLOID, -1, 0);
+		TupleDescInitEntry(tupledesc, (AttrNumber) 8, "usage_count",
+						   INT2OID, -1, 0);
+
+		fctx->tupdesc = BlessTupleDesc(tupledesc);
+
+		/* Allocate NBuffers worth of BufferCachePagesRec records. */
+		fctx->record = (BufferCachePagesRec *) palloc(sizeof(BufferCachePagesRec) * NBuffers);
+
+		/* Set max calls and remember the user function context. */
+		funcctx->max_calls = NBuffers;
+		funcctx->user_fctx = fctx;
+
+		/* Return to original context when allocating transient memory */
+		MemoryContextSwitchTo(oldcontext);
+
+		/*
+		 * To get a consistent picture of the buffer state, we must lock all
+		 * partitions of the buffer map.  Needless to say, this is horrible
+		 * for concurrency.  Must grab locks in increasing order to avoid
+		 * possible deadlocks.
+		 */
+		for (i = 0; i < NUM_BUFFER_PARTITIONS; i++)
+			LWLockAcquire(FirstBufMappingLock + i, LW_SHARED);
+
+		/*
+		 * Scan though all the buffers, saving the relevant fields in the
+		 * fctx->record structure.
+		 */
+		for (i = 0, bufHdr = BufferDescriptors; i < NBuffers; i++, bufHdr++)
+		{
+			/* Lock each buffer header before inspecting. */
+			LockBufHdr(bufHdr);
+
+			fctx->record[i].bufferid = BufferDescriptorGetBuffer(bufHdr);
+			fctx->record[i].relfilenode = bufHdr->tag.rnode.relNode;
+			fctx->record[i].reltablespace = bufHdr->tag.rnode.spcNode;
+			fctx->record[i].reldatabase = bufHdr->tag.rnode.dbNode;
+			fctx->record[i].forknum = bufHdr->tag.forkNum;
+			fctx->record[i].blocknum = bufHdr->tag.blockNum;
+			fctx->record[i].usagecount = bufHdr->usage_count;
+
+			if (bufHdr->flags & BM_DIRTY)
+				fctx->record[i].isdirty = true;
+			else
+				fctx->record[i].isdirty = false;
+
+			/* Note if the buffer is valid, and has storage created */
+			if ((bufHdr->flags & BM_VALID) && (bufHdr->flags & BM_TAG_VALID))
+				fctx->record[i].isvalid = true;
+			else
+				fctx->record[i].isvalid = false;
+
+			UnlockBufHdr(bufHdr);
+		}
+
+		/*
+		 * And release locks.  We do this in reverse order for two reasons:
+		 * (1) Anyone else who needs more than one of the locks will be trying
+		 * to lock them in increasing order; we don't want to release the
+		 * other process until it can get all the locks it needs. (2) This
+		 * avoids O(N^2) behavior inside LWLockRelease.
+		 */
+		for (i = NUM_BUFFER_PARTITIONS; --i >= 0;)
+			LWLockRelease(FirstBufMappingLock + i);
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+
+	/* Get the saved state */
+	fctx = funcctx->user_fctx;
+
+	if (funcctx->call_cntr < funcctx->max_calls)
+	{
+		uint32		i = funcctx->call_cntr;
+		Datum		values[NUM_BUFFERCACHE_PAGES_ELEM];
+		bool		nulls[NUM_BUFFERCACHE_PAGES_ELEM];
+
+		values[0] = Int32GetDatum(fctx->record[i].bufferid);
+		nulls[0] = false;
+
+		/*
+		 * Set all fields except the bufferid to null if the buffer is unused
+		 * or not valid.
+		 */
+		if (fctx->record[i].blocknum == InvalidBlockNumber ||
+			fctx->record[i].isvalid == false)
+		{
+			nulls[1] = true;
+			nulls[2] = true;
+			nulls[3] = true;
+			nulls[4] = true;
+			nulls[5] = true;
+			nulls[6] = true;
+			nulls[7] = true;
+		}
+		else
+		{
+			values[1] = ObjectIdGetDatum(fctx->record[i].relfilenode);
+			nulls[1] = false;
+			values[2] = ObjectIdGetDatum(fctx->record[i].reltablespace);
+			nulls[2] = false;
+			values[3] = ObjectIdGetDatum(fctx->record[i].reldatabase);
+			nulls[3] = false;
+			values[4] = ObjectIdGetDatum(fctx->record[i].forknum);
+			nulls[4] = false;
+			values[5] = Int64GetDatum((int64) fctx->record[i].blocknum);
+			nulls[5] = false;
+			values[6] = BoolGetDatum(fctx->record[i].isdirty);
+			nulls[6] = false;
+			values[7] = Int16GetDatum(fctx->record[i].usagecount);
+			nulls[7] = false;
+		}
+
+		/* Build and return the tuple. */
+		tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
+		result = HeapTupleGetDatum(tuple);
+
+		SRF_RETURN_NEXT(funcctx, result);
+	}
+	else
+		SRF_RETURN_DONE(funcctx);
+}
diff --git a/src/extension/pg_freespacemap/Makefile b/src/extension/pg_freespacemap/Makefile
new file mode 100644
index 0000000..0ffe226
--- /dev/null
+++ b/src/extension/pg_freespacemap/Makefile
@@ -0,0 +1,19 @@
+# src/extensions/pg_freespacemap/Makefile
+
+MODULE_big = pg_freespacemap
+OBJS = pg_freespacemap.o
+MODULEDIR = extension
+
+EXTENSION = pg_freespacemap
+DATA = pg_freespacemap--1.0.sql pg_freespacemap--unpackaged--1.0.sql
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/extension/pg_freespacemap
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/src/extension/extension-global.mk
+endif
diff --git a/src/extension/pg_freespacemap/pg_freespacemap--1.0.sql b/src/extension/pg_freespacemap/pg_freespacemap--1.0.sql
new file mode 100644
index 0000000..8188786
--- /dev/null
+++ b/src/extension/pg_freespacemap/pg_freespacemap--1.0.sql
@@ -0,0 +1,22 @@
+/* src/extensions/pg_freespacemap/pg_freespacemap--1.0.sql */
+
+-- Register the C function.
+CREATE FUNCTION pg_freespace(regclass, bigint)
+RETURNS int2
+AS 'MODULE_PATHNAME', 'pg_freespace'
+LANGUAGE C STRICT;
+
+-- pg_freespace shows the recorded space avail at each block in a relation
+CREATE FUNCTION
+  pg_freespace(rel regclass, blkno OUT bigint, avail OUT int2)
+RETURNS SETOF RECORD
+AS $$
+  SELECT blkno, pg_freespace($1, blkno) AS avail
+  FROM generate_series(0, pg_relation_size($1) / current_setting('block_size')::bigint - 1) AS blkno;
+$$
+LANGUAGE SQL;
+
+
+-- Don't want these to be available to public.
+REVOKE ALL ON FUNCTION pg_freespace(regclass, bigint) FROM PUBLIC;
+REVOKE ALL ON FUNCTION pg_freespace(regclass) FROM PUBLIC;
diff --git a/src/extension/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql b/src/extension/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql
new file mode 100644
index 0000000..d2231ef
--- /dev/null
+++ b/src/extension/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql
@@ -0,0 +1,4 @@
+/* src/extensions/pg_freespacemap/pg_freespacemap--unpackaged--1.0.sql */
+
+ALTER EXTENSION pg_freespacemap ADD function pg_freespace(regclass,bigint);
+ALTER EXTENSION pg_freespacemap ADD function pg_freespace(regclass);
diff --git a/src/extension/pg_freespacemap/pg_freespacemap.c b/src/extension/pg_freespacemap/pg_freespacemap.c
new file mode 100644
index 0000000..501da04
--- /dev/null
+++ b/src/extension/pg_freespacemap/pg_freespacemap.c
@@ -0,0 +1,46 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_freespacemap.c
+ *	  display contents of a free space map
+ *
+ *	  src/extensions/pg_freespacemap/pg_freespacemap.c
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "funcapi.h"
+#include "storage/block.h"
+#include "storage/freespace.h"
+
+
+PG_MODULE_MAGIC;
+
+Datum		pg_freespace(PG_FUNCTION_ARGS);
+
+/*
+ * Returns the amount of free space on a given page, according to the
+ * free space map.
+ */
+PG_FUNCTION_INFO_V1(pg_freespace);
+
+Datum
+pg_freespace(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int64		blkno = PG_GETARG_INT64(1);
+	int16		freespace;
+	Relation	rel;
+
+	rel = relation_open(relid, AccessShareLock);
+
+	if (blkno < 0 || blkno > MaxBlockNumber)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid block number")));
+
+	freespace = GetRecordedFreeSpace(rel, blkno);
+
+	relation_close(rel, AccessShareLock);
+	PG_RETURN_INT16(freespace);
+}
diff --git a/src/extension/pg_freespacemap/pg_freespacemap.control b/src/extension/pg_freespacemap/pg_freespacemap.control
new file mode 100644
index 0000000..34b695f
--- /dev/null
+++ b/src/extension/pg_freespacemap/pg_freespacemap.control
@@ -0,0 +1,5 @@
+# pg_freespacemap extension
+comment = 'examine the free space map (FSM)'
+default_version = '1.0'
+module_pathname = '$libdir/pg_freespacemap'
+relocatable = true
diff --git a/src/extension/pg_stat_statements/Makefile b/src/extension/pg_stat_statements/Makefile
new file mode 100644
index 0000000..9cf3f99
--- /dev/null
+++ b/src/extension/pg_stat_statements/Makefile
@@ -0,0 +1,19 @@
+# src/extension/pg_stat_statements/Makefile
+
+MODULE_big = pg_stat_statements
+OBJS = pg_stat_statements.o
+MODULEDIR = extension
+
+EXTENSION = pg_stat_statements
+DATA = pg_stat_statements--1.0.sql pg_stat_statements--unpackaged--1.0.sql
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/extension/pg_stat_statements
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/src/extension/extension-global.mk
+endif
diff --git a/src/extension/pg_stat_statements/pg_stat_statements--1.0.sql b/src/extension/pg_stat_statements/pg_stat_statements--1.0.sql
new file mode 100644
index 0000000..41145e7
--- /dev/null
+++ b/src/extension/pg_stat_statements/pg_stat_statements--1.0.sql
@@ -0,0 +1,36 @@
+/* src/extension/pg_stat_statements/pg_stat_statements--1.0.sql */
+
+-- Register functions.
+CREATE FUNCTION pg_stat_statements_reset()
+RETURNS void
+AS 'MODULE_PATHNAME'
+LANGUAGE C;
+
+CREATE FUNCTION pg_stat_statements(
+    OUT userid oid,
+    OUT dbid oid,
+    OUT query text,
+    OUT calls int8,
+    OUT total_time float8,
+    OUT rows int8,
+    OUT shared_blks_hit int8,
+    OUT shared_blks_read int8,
+    OUT shared_blks_written int8,
+    OUT local_blks_hit int8,
+    OUT local_blks_read int8,
+    OUT local_blks_written int8,
+    OUT temp_blks_read int8,
+    OUT temp_blks_written int8
+)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME'
+LANGUAGE C;
+
+-- Register a view on the function for ease of use.
+CREATE VIEW pg_stat_statements AS
+  SELECT * FROM pg_stat_statements();
+
+GRANT SELECT ON pg_stat_statements TO PUBLIC;
+
+-- Don't want this to be available to non-superusers.
+REVOKE ALL ON FUNCTION pg_stat_statements_reset() FROM PUBLIC;
diff --git a/src/extension/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql b/src/extension/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql
new file mode 100644
index 0000000..c8993b5
--- /dev/null
+++ b/src/extension/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql
@@ -0,0 +1,5 @@
+/* src/extension/pg_stat_statements/pg_stat_statements--unpackaged--1.0.sql */
+
+ALTER EXTENSION pg_stat_statements ADD function pg_stat_statements_reset();
+ALTER EXTENSION pg_stat_statements ADD function pg_stat_statements();
+ALTER EXTENSION pg_stat_statements ADD view pg_stat_statements;
diff --git a/src/extension/pg_stat_statements/pg_stat_statements.c b/src/extension/pg_stat_statements/pg_stat_statements.c
new file mode 100644
index 0000000..4ecd445
--- /dev/null
+++ b/src/extension/pg_stat_statements/pg_stat_statements.c
@@ -0,0 +1,1046 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_stat_statements.c
+ *		Track statement execution times across a whole database cluster.
+ *
+ * Note about locking issues: to create or delete an entry in the shared
+ * hashtable, one must hold pgss->lock exclusively.  Modifying any field
+ * in an entry except the counters requires the same.  To look up an entry,
+ * one must hold the lock shared.  To read or update the counters within
+ * an entry, one must hold the lock shared or exclusive (so the entry doesn't
+ * disappear!) and also take the entry's mutex spinlock.
+ *
+ *
+ * Copyright (c) 2008-2011, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/test/pg_stat_statements/pg_stat_statements.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include <unistd.h>
+
+#include "access/hash.h"
+#include "catalog/pg_type.h"
+#include "executor/executor.h"
+#include "executor/instrument.h"
+#include "funcapi.h"
+#include "mb/pg_wchar.h"
+#include "miscadmin.h"
+#include "pgstat.h"
+#include "storage/fd.h"
+#include "storage/ipc.h"
+#include "storage/spin.h"
+#include "tcop/utility.h"
+#include "utils/builtins.h"
+#include "utils/hsearch.h"
+#include "utils/guc.h"
+
+
+PG_MODULE_MAGIC;
+
+/* Location of stats file */
+#define PGSS_DUMP_FILE	"global/pg_stat_statements.stat"
+
+/* This constant defines the magic number in the stats file header */
+static const uint32 PGSS_FILE_HEADER = 0x20100108;
+
+/* XXX: Should USAGE_EXEC reflect execution time and/or buffer usage? */
+#define USAGE_EXEC(duration)	(1.0)
+#define USAGE_INIT				(1.0)	/* including initial planning */
+#define USAGE_DECREASE_FACTOR	(0.99)	/* decreased every entry_dealloc */
+#define USAGE_DEALLOC_PERCENT	5		/* free this % of entries at once */
+
+/*
+ * Hashtable key that defines the identity of a hashtable entry.  The
+ * hash comparators do not assume that the query string is null-terminated;
+ * this lets us search for an mbcliplen'd string without copying it first.
+ *
+ * Presently, the query encoding is fully determined by the source database
+ * and so we don't really need it to be in the key.  But that might not always
+ * be true. Anyway it's notationally convenient to pass it as part of the key.
+ */
+typedef struct pgssHashKey
+{
+	Oid			userid;			/* user OID */
+	Oid			dbid;			/* database OID */
+	int			encoding;		/* query encoding */
+	int			query_len;		/* # of valid bytes in query string */
+	const char *query_ptr;		/* query string proper */
+} pgssHashKey;
+
+/*
+ * The actual stats counters kept within pgssEntry.
+ */
+typedef struct Counters
+{
+	int64		calls;			/* # of times executed */
+	double		total_time;		/* total execution time in seconds */
+	int64		rows;			/* total # of retrieved or affected rows */
+	int64		shared_blks_hit;	/* # of shared buffer hits */
+	int64		shared_blks_read;		/* # of shared disk blocks read */
+	int64		shared_blks_written;	/* # of shared disk blocks written */
+	int64		local_blks_hit; /* # of local buffer hits */
+	int64		local_blks_read;	/* # of local disk blocks read */
+	int64		local_blks_written;		/* # of local disk blocks written */
+	int64		temp_blks_read; /* # of temp blocks read */
+	int64		temp_blks_written;		/* # of temp blocks written */
+	double		usage;			/* usage factor */
+} Counters;
+
+/*
+ * Statistics per statement
+ *
+ * NB: see the file read/write code before changing field order here.
+ */
+typedef struct pgssEntry
+{
+	pgssHashKey key;			/* hash key of entry - MUST BE FIRST */
+	Counters	counters;		/* the statistics for this query */
+	slock_t		mutex;			/* protects the counters only */
+	char		query[1];		/* VARIABLE LENGTH ARRAY - MUST BE LAST */
+	/* Note: the allocated length of query[] is actually pgss->query_size */
+} pgssEntry;
+
+/*
+ * Global shared state
+ */
+typedef struct pgssSharedState
+{
+	LWLockId	lock;			/* protects hashtable search/modification */
+	int			query_size;		/* max query length in bytes */
+} pgssSharedState;
+
+/*---- Local variables ----*/
+
+/* Current nesting depth of ExecutorRun calls */
+static int	nested_level = 0;
+
+/* Saved hook values in case of unload */
+static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
+static ExecutorStart_hook_type prev_ExecutorStart = NULL;
+static ExecutorRun_hook_type prev_ExecutorRun = NULL;
+static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
+static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
+static ProcessUtility_hook_type prev_ProcessUtility = NULL;
+
+/* Links to shared memory state */
+static pgssSharedState *pgss = NULL;
+static HTAB *pgss_hash = NULL;
+
+/*---- GUC variables ----*/
+
+typedef enum
+{
+	PGSS_TRACK_NONE,			/* track no statements */
+	PGSS_TRACK_TOP,				/* only top level statements */
+	PGSS_TRACK_ALL				/* all statements, including nested ones */
+}	PGSSTrackLevel;
+
+static const struct config_enum_entry track_options[] =
+{
+	{"none", PGSS_TRACK_NONE, false},
+	{"top", PGSS_TRACK_TOP, false},
+	{"all", PGSS_TRACK_ALL, false},
+	{NULL, 0, false}
+};
+
+static int	pgss_max;			/* max # statements to track */
+static int	pgss_track;			/* tracking level */
+static bool pgss_track_utility; /* whether to track utility commands */
+static bool pgss_save;			/* whether to save stats across shutdown */
+
+
+#define pgss_enabled() \
+	(pgss_track == PGSS_TRACK_ALL || \
+	(pgss_track == PGSS_TRACK_TOP && nested_level == 0))
+
+/*---- Function declarations ----*/
+
+void		_PG_init(void);
+void		_PG_fini(void);
+
+Datum		pg_stat_statements_reset(PG_FUNCTION_ARGS);
+Datum		pg_stat_statements(PG_FUNCTION_ARGS);
+
+PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
+PG_FUNCTION_INFO_V1(pg_stat_statements);
+
+static void pgss_shmem_startup(void);
+static void pgss_shmem_shutdown(int code, Datum arg);
+static void pgss_ExecutorStart(QueryDesc *queryDesc, int eflags);
+static void pgss_ExecutorRun(QueryDesc *queryDesc,
+				 ScanDirection direction,
+				 long count);
+static void pgss_ExecutorFinish(QueryDesc *queryDesc);
+static void pgss_ExecutorEnd(QueryDesc *queryDesc);
+static void pgss_ProcessUtility(Node *parsetree,
+			  const char *queryString, ParamListInfo params, bool isTopLevel,
+					DestReceiver *dest, char *completionTag);
+static uint32 pgss_hash_fn(const void *key, Size keysize);
+static int	pgss_match_fn(const void *key1, const void *key2, Size keysize);
+static void pgss_store(const char *query, double total_time, uint64 rows,
+		   const BufferUsage *bufusage);
+static Size pgss_memsize(void);
+static pgssEntry *entry_alloc(pgssHashKey *key);
+static void entry_dealloc(void);
+static void entry_reset(void);
+
+
+/*
+ * Module load callback
+ */
+void
+_PG_init(void)
+{
+	/*
+	 * In order to create our shared memory area, we have to be loaded via
+	 * shared_preload_libraries.  If not, fall out without hooking into any of
+	 * the main system.  (We don't throw error here because it seems useful to
+	 * allow the pg_stat_statements functions to be created even when the
+	 * module isn't active.  The functions must protect themselves against
+	 * being called then, however.)
+	 */
+	if (!process_shared_preload_libraries_in_progress)
+		return;
+
+	/*
+	 * Define (or redefine) custom GUC variables.
+	 */
+	DefineCustomIntVariable("pg_stat_statements.max",
+	  "Sets the maximum number of statements tracked by pg_stat_statements.",
+							NULL,
+							&pgss_max,
+							1000,
+							100,
+							INT_MAX,
+							PGC_POSTMASTER,
+							0,
+							NULL,
+							NULL,
+							NULL);
+
+	DefineCustomEnumVariable("pg_stat_statements.track",
+			   "Selects which statements are tracked by pg_stat_statements.",
+							 NULL,
+							 &pgss_track,
+							 PGSS_TRACK_TOP,
+							 track_options,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	DefineCustomBoolVariable("pg_stat_statements.track_utility",
+	   "Selects whether utility commands are tracked by pg_stat_statements.",
+							 NULL,
+							 &pgss_track_utility,
+							 true,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	DefineCustomBoolVariable("pg_stat_statements.save",
+			   "Save pg_stat_statements statistics across server shutdowns.",
+							 NULL,
+							 &pgss_save,
+							 true,
+							 PGC_SIGHUP,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
+	EmitWarningsOnPlaceholders("pg_stat_statements");
+
+	/*
+	 * Request additional shared resources.  (These are no-ops if we're not in
+	 * the postmaster process.)  We'll allocate or attach to the shared
+	 * resources in pgss_shmem_startup().
+	 */
+	RequestAddinShmemSpace(pgss_memsize());
+	RequestAddinLWLocks(1);
+
+	/*
+	 * Install hooks.
+	 */
+	prev_shmem_startup_hook = shmem_startup_hook;
+	shmem_startup_hook = pgss_shmem_startup;
+	prev_ExecutorStart = ExecutorStart_hook;
+	ExecutorStart_hook = pgss_ExecutorStart;
+	prev_ExecutorRun = ExecutorRun_hook;
+	ExecutorRun_hook = pgss_ExecutorRun;
+	prev_ExecutorFinish = ExecutorFinish_hook;
+	ExecutorFinish_hook = pgss_ExecutorFinish;
+	prev_ExecutorEnd = ExecutorEnd_hook;
+	ExecutorEnd_hook = pgss_ExecutorEnd;
+	prev_ProcessUtility = ProcessUtility_hook;
+	ProcessUtility_hook = pgss_ProcessUtility;
+}
+
+/*
+ * Module unload callback
+ */
+void
+_PG_fini(void)
+{
+	/* Uninstall hooks. */
+	shmem_startup_hook = prev_shmem_startup_hook;
+	ExecutorStart_hook = prev_ExecutorStart;
+	ExecutorRun_hook = prev_ExecutorRun;
+	ExecutorFinish_hook = prev_ExecutorFinish;
+	ExecutorEnd_hook = prev_ExecutorEnd;
+	ProcessUtility_hook = prev_ProcessUtility;
+}
+
+/*
+ * shmem_startup hook: allocate or attach to shared memory,
+ * then load any pre-existing statistics from file.
+ */
+static void
+pgss_shmem_startup(void)
+{
+	bool		found;
+	HASHCTL		info;
+	FILE	   *file;
+	uint32		header;
+	int32		num;
+	int32		i;
+	int			query_size;
+	int			buffer_size;
+	char	   *buffer = NULL;
+
+	if (prev_shmem_startup_hook)
+		prev_shmem_startup_hook();
+
+	/* reset in case this is a restart within the postmaster */
+	pgss = NULL;
+	pgss_hash = NULL;
+
+	/*
+	 * Create or attach to the shared memory state, including hash table
+	 */
+	LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+	pgss = ShmemInitStruct("pg_stat_statements",
+						   sizeof(pgssSharedState),
+						   &found);
+
+	if (!found)
+	{
+		/* First time through ... */
+		pgss->lock = LWLockAssign();
+		pgss->query_size = pgstat_track_activity_query_size;
+	}
+
+	/* Be sure everyone agrees on the hash table entry size */
+	query_size = pgss->query_size;
+
+	memset(&info, 0, sizeof(info));
+	info.keysize = sizeof(pgssHashKey);
+	info.entrysize = offsetof(pgssEntry, query) +query_size;
+	info.hash = pgss_hash_fn;
+	info.match = pgss_match_fn;
+	pgss_hash = ShmemInitHash("pg_stat_statements hash",
+							  pgss_max, pgss_max,
+							  &info,
+							  HASH_ELEM | HASH_FUNCTION | HASH_COMPARE);
+
+	LWLockRelease(AddinShmemInitLock);
+
+	/*
+	 * If we're in the postmaster (or a standalone backend...), set up a shmem
+	 * exit hook to dump the statistics to disk.
+	 */
+	if (!IsUnderPostmaster)
+		on_shmem_exit(pgss_shmem_shutdown, (Datum) 0);
+
+	/*
+	 * Attempt to load old statistics from the dump file, if this is the first
+	 * time through and we weren't told not to.
+	 */
+	if (found || !pgss_save)
+		return;
+
+	/*
+	 * Note: we don't bother with locks here, because there should be no other
+	 * processes running when this code is reached.
+	 */
+	file = AllocateFile(PGSS_DUMP_FILE, PG_BINARY_R);
+	if (file == NULL)
+	{
+		if (errno == ENOENT)
+			return;				/* ignore not-found error */
+		goto error;
+	}
+
+	buffer_size = query_size;
+	buffer = (char *) palloc(buffer_size);
+
+	if (fread(&header, sizeof(uint32), 1, file) != 1 ||
+		header != PGSS_FILE_HEADER ||
+		fread(&num, sizeof(int32), 1, file) != 1)
+		goto error;
+
+	for (i = 0; i < num; i++)
+	{
+		pgssEntry	temp;
+		pgssEntry  *entry;
+
+		if (fread(&temp, offsetof(pgssEntry, mutex), 1, file) != 1)
+			goto error;
+
+		/* Encoding is the only field we can easily sanity-check */
+		if (!PG_VALID_BE_ENCODING(temp.key.encoding))
+			goto error;
+
+		/* Previous incarnation might have had a larger query_size */
+		if (temp.key.query_len >= buffer_size)
+		{
+			buffer = (char *) repalloc(buffer, temp.key.query_len + 1);
+			buffer_size = temp.key.query_len + 1;
+		}
+
+		if (fread(buffer, 1, temp.key.query_len, file) != temp.key.query_len)
+			goto error;
+		buffer[temp.key.query_len] = '\0';
+
+		/* Clip to available length if needed */
+		if (temp.key.query_len >= query_size)
+			temp.key.query_len = pg_encoding_mbcliplen(temp.key.encoding,
+													   buffer,
+													   temp.key.query_len,
+													   query_size - 1);
+		temp.key.query_ptr = buffer;
+
+		/* make the hashtable entry (discards old entries if too many) */
+		entry = entry_alloc(&temp.key);
+
+		/* copy in the actual stats */
+		entry->counters = temp.counters;
+	}
+
+	pfree(buffer);
+	FreeFile(file);
+	return;
+
+error:
+	ereport(LOG,
+			(errcode_for_file_access(),
+			 errmsg("could not read pg_stat_statement file \"%s\": %m",
+					PGSS_DUMP_FILE)));
+	if (buffer)
+		pfree(buffer);
+	if (file)
+		FreeFile(file);
+	/* If possible, throw away the bogus file; ignore any error */
+	unlink(PGSS_DUMP_FILE);
+}
+
+/*
+ * shmem_shutdown hook: Dump statistics into file.
+ *
+ * Note: we don't bother with acquiring lock, because there should be no
+ * other processes running when this is called.
+ */
+static void
+pgss_shmem_shutdown(int code, Datum arg)
+{
+	FILE	   *file;
+	HASH_SEQ_STATUS hash_seq;
+	int32		num_entries;
+	pgssEntry  *entry;
+
+	/* Don't try to dump during a crash. */
+	if (code)
+		return;
+
+	/* Safety check ... shouldn't get here unless shmem is set up. */
+	if (!pgss || !pgss_hash)
+		return;
+
+	/* Don't dump if told not to. */
+	if (!pgss_save)
+		return;
+
+	file = AllocateFile(PGSS_DUMP_FILE, PG_BINARY_W);
+	if (file == NULL)
+		goto error;
+
+	if (fwrite(&PGSS_FILE_HEADER, sizeof(uint32), 1, file) != 1)
+		goto error;
+	num_entries = hash_get_num_entries(pgss_hash);
+	if (fwrite(&num_entries, sizeof(int32), 1, file) != 1)
+		goto error;
+
+	hash_seq_init(&hash_seq, pgss_hash);
+	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	{
+		int			len = entry->key.query_len;
+
+		if (fwrite(entry, offsetof(pgssEntry, mutex), 1, file) != 1 ||
+			fwrite(entry->query, 1, len, file) != len)
+			goto error;
+	}
+
+	if (FreeFile(file))
+	{
+		file = NULL;
+		goto error;
+	}
+
+	return;
+
+error:
+	ereport(LOG,
+			(errcode_for_file_access(),
+			 errmsg("could not write pg_stat_statement file \"%s\": %m",
+					PGSS_DUMP_FILE)));
+	if (file)
+		FreeFile(file);
+	unlink(PGSS_DUMP_FILE);
+}
+
+/*
+ * ExecutorStart hook: start up tracking if needed
+ */
+static void
+pgss_ExecutorStart(QueryDesc *queryDesc, int eflags)
+{
+	if (prev_ExecutorStart)
+		prev_ExecutorStart(queryDesc, eflags);
+	else
+		standard_ExecutorStart(queryDesc, eflags);
+
+	if (pgss_enabled())
+	{
+		/*
+		 * Set up to track total elapsed time in ExecutorRun.  Make sure the
+		 * space is allocated in the per-query context so it will go away at
+		 * ExecutorEnd.
+		 */
+		if (queryDesc->totaltime == NULL)
+		{
+			MemoryContext oldcxt;
+
+			oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
+			queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL);
+			MemoryContextSwitchTo(oldcxt);
+		}
+	}
+}
+
+/*
+ * ExecutorRun hook: all we need do is track nesting depth
+ */
+static void
+pgss_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count)
+{
+	nested_level++;
+	PG_TRY();
+	{
+		if (prev_ExecutorRun)
+			prev_ExecutorRun(queryDesc, direction, count);
+		else
+			standard_ExecutorRun(queryDesc, direction, count);
+		nested_level--;
+	}
+	PG_CATCH();
+	{
+		nested_level--;
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+}
+
+/*
+ * ExecutorFinish hook: all we need do is track nesting depth
+ */
+static void
+pgss_ExecutorFinish(QueryDesc *queryDesc)
+{
+	nested_level++;
+	PG_TRY();
+	{
+		if (prev_ExecutorFinish)
+			prev_ExecutorFinish(queryDesc);
+		else
+			standard_ExecutorFinish(queryDesc);
+		nested_level--;
+	}
+	PG_CATCH();
+	{
+		nested_level--;
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+}
+
+/*
+ * ExecutorEnd hook: store results if needed
+ */
+static void
+pgss_ExecutorEnd(QueryDesc *queryDesc)
+{
+	if (queryDesc->totaltime && pgss_enabled())
+	{
+		/*
+		 * Make sure stats accumulation is done.  (Note: it's okay if several
+		 * levels of hook all do this.)
+		 */
+		InstrEndLoop(queryDesc->totaltime);
+
+		pgss_store(queryDesc->sourceText,
+				   queryDesc->totaltime->total,
+				   queryDesc->estate->es_processed,
+				   &queryDesc->totaltime->bufusage);
+	}
+
+	if (prev_ExecutorEnd)
+		prev_ExecutorEnd(queryDesc);
+	else
+		standard_ExecutorEnd(queryDesc);
+}
+
+/*
+ * ProcessUtility hook
+ */
+static void
+pgss_ProcessUtility(Node *parsetree, const char *queryString,
+					ParamListInfo params, bool isTopLevel,
+					DestReceiver *dest, char *completionTag)
+{
+	if (pgss_track_utility && pgss_enabled())
+	{
+		instr_time	start;
+		instr_time	duration;
+		uint64		rows = 0;
+		BufferUsage bufusage;
+
+		bufusage = pgBufferUsage;
+		INSTR_TIME_SET_CURRENT(start);
+
+		nested_level++;
+		PG_TRY();
+		{
+			if (prev_ProcessUtility)
+				prev_ProcessUtility(parsetree, queryString, params,
+									isTopLevel, dest, completionTag);
+			else
+				standard_ProcessUtility(parsetree, queryString, params,
+										isTopLevel, dest, completionTag);
+			nested_level--;
+		}
+		PG_CATCH();
+		{
+			nested_level--;
+			PG_RE_THROW();
+		}
+		PG_END_TRY();
+
+		INSTR_TIME_SET_CURRENT(duration);
+		INSTR_TIME_SUBTRACT(duration, start);
+
+		/* parse command tag to retrieve the number of affected rows. */
+		if (completionTag &&
+			sscanf(completionTag, "COPY " UINT64_FORMAT, &rows) != 1)
+			rows = 0;
+
+		/* calc differences of buffer counters. */
+		bufusage.shared_blks_hit =
+			pgBufferUsage.shared_blks_hit - bufusage.shared_blks_hit;
+		bufusage.shared_blks_read =
+			pgBufferUsage.shared_blks_read - bufusage.shared_blks_read;
+		bufusage.shared_blks_written =
+			pgBufferUsage.shared_blks_written - bufusage.shared_blks_written;
+		bufusage.local_blks_hit =
+			pgBufferUsage.local_blks_hit - bufusage.local_blks_hit;
+		bufusage.local_blks_read =
+			pgBufferUsage.local_blks_read - bufusage.local_blks_read;
+		bufusage.local_blks_written =
+			pgBufferUsage.local_blks_written - bufusage.local_blks_written;
+		bufusage.temp_blks_read =
+			pgBufferUsage.temp_blks_read - bufusage.temp_blks_read;
+		bufusage.temp_blks_written =
+			pgBufferUsage.temp_blks_written - bufusage.temp_blks_written;
+
+		pgss_store(queryString, INSTR_TIME_GET_DOUBLE(duration), rows,
+				   &bufusage);
+	}
+	else
+	{
+		if (prev_ProcessUtility)
+			prev_ProcessUtility(parsetree, queryString, params,
+								isTopLevel, dest, completionTag);
+		else
+			standard_ProcessUtility(parsetree, queryString, params,
+									isTopLevel, dest, completionTag);
+	}
+}
+
+/*
+ * Calculate hash value for a key
+ */
+static uint32
+pgss_hash_fn(const void *key, Size keysize)
+{
+	const pgssHashKey *k = (const pgssHashKey *) key;
+
+	/* we don't bother to include encoding in the hash */
+	return hash_uint32((uint32) k->userid) ^
+		hash_uint32((uint32) k->dbid) ^
+		DatumGetUInt32(hash_any((const unsigned char *) k->query_ptr,
+								k->query_len));
+}
+
+/*
+ * Compare two keys - zero means match
+ */
+static int
+pgss_match_fn(const void *key1, const void *key2, Size keysize)
+{
+	const pgssHashKey *k1 = (const pgssHashKey *) key1;
+	const pgssHashKey *k2 = (const pgssHashKey *) key2;
+
+	if (k1->userid == k2->userid &&
+		k1->dbid == k2->dbid &&
+		k1->encoding == k2->encoding &&
+		k1->query_len == k2->query_len &&
+		memcmp(k1->query_ptr, k2->query_ptr, k1->query_len) == 0)
+		return 0;
+	else
+		return 1;
+}
+
+/*
+ * Store some statistics for a statement.
+ */
+static void
+pgss_store(const char *query, double total_time, uint64 rows,
+		   const BufferUsage *bufusage)
+{
+	pgssHashKey key;
+	double		usage;
+	pgssEntry  *entry;
+
+	Assert(query != NULL);
+
+	/* Safety check... */
+	if (!pgss || !pgss_hash)
+		return;
+
+	/* Set up key for hashtable search */
+	key.userid = GetUserId();
+	key.dbid = MyDatabaseId;
+	key.encoding = GetDatabaseEncoding();
+	key.query_len = strlen(query);
+	if (key.query_len >= pgss->query_size)
+		key.query_len = pg_encoding_mbcliplen(key.encoding,
+											  query,
+											  key.query_len,
+											  pgss->query_size - 1);
+	key.query_ptr = query;
+
+	usage = USAGE_EXEC(duration);
+
+	/* Lookup the hash table entry with shared lock. */
+	LWLockAcquire(pgss->lock, LW_SHARED);
+
+	entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
+	if (!entry)
+	{
+		/* Must acquire exclusive lock to add a new entry. */
+		LWLockRelease(pgss->lock);
+		LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
+		entry = entry_alloc(&key);
+	}
+
+	/* Grab the spinlock while updating the counters. */
+	{
+		volatile pgssEntry *e = (volatile pgssEntry *) entry;
+
+		SpinLockAcquire(&e->mutex);
+		e->counters.calls += 1;
+		e->counters.total_time += total_time;
+		e->counters.rows += rows;
+		e->counters.shared_blks_hit += bufusage->shared_blks_hit;
+		e->counters.shared_blks_read += bufusage->shared_blks_read;
+		e->counters.shared_blks_written += bufusage->shared_blks_written;
+		e->counters.local_blks_hit += bufusage->local_blks_hit;
+		e->counters.local_blks_read += bufusage->local_blks_read;
+		e->counters.local_blks_written += bufusage->local_blks_written;
+		e->counters.temp_blks_read += bufusage->temp_blks_read;
+		e->counters.temp_blks_written += bufusage->temp_blks_written;
+		e->counters.usage += usage;
+		SpinLockRelease(&e->mutex);
+	}
+
+	LWLockRelease(pgss->lock);
+}
+
+/*
+ * Reset all statement statistics.
+ */
+Datum
+pg_stat_statements_reset(PG_FUNCTION_ARGS)
+{
+	if (!pgss || !pgss_hash)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
+	entry_reset();
+	PG_RETURN_VOID();
+}
+
+#define PG_STAT_STATEMENTS_COLS		14
+
+/*
+ * Retrieve statement statistics.
+ */
+Datum
+pg_stat_statements(PG_FUNCTION_ARGS)
+{
+	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc	tupdesc;
+	Tuplestorestate *tupstore;
+	MemoryContext per_query_ctx;
+	MemoryContext oldcontext;
+	Oid			userid = GetUserId();
+	bool		is_superuser = superuser();
+	HASH_SEQ_STATUS hash_seq;
+	pgssEntry  *entry;
+
+	if (!pgss || !pgss_hash)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
+
+	/* check to see if caller supports us returning a tuplestore */
+	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("set-valued function called in context that cannot accept a set")));
+	if (!(rsinfo->allowedModes & SFRM_Materialize))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("materialize mode required, but it is not " \
+						"allowed in this context")));
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
+	oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+	tupstore = tuplestore_begin_heap(true, false, work_mem);
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = tupstore;
+	rsinfo->setDesc = tupdesc;
+
+	MemoryContextSwitchTo(oldcontext);
+
+	LWLockAcquire(pgss->lock, LW_SHARED);
+
+	hash_seq_init(&hash_seq, pgss_hash);
+	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	{
+		Datum		values[PG_STAT_STATEMENTS_COLS];
+		bool		nulls[PG_STAT_STATEMENTS_COLS];
+		int			i = 0;
+		Counters	tmp;
+
+		memset(values, 0, sizeof(values));
+		memset(nulls, 0, sizeof(nulls));
+
+		values[i++] = ObjectIdGetDatum(entry->key.userid);
+		values[i++] = ObjectIdGetDatum(entry->key.dbid);
+
+		if (is_superuser || entry->key.userid == userid)
+		{
+			char	   *qstr;
+
+			qstr = (char *)
+				pg_do_encoding_conversion((unsigned char *) entry->query,
+										  entry->key.query_len,
+										  entry->key.encoding,
+										  GetDatabaseEncoding());
+			values[i++] = CStringGetTextDatum(qstr);
+			if (qstr != entry->query)
+				pfree(qstr);
+		}
+		else
+			values[i++] = CStringGetTextDatum("<insufficient privilege>");
+
+		/* copy counters to a local variable to keep locking time short */
+		{
+			volatile pgssEntry *e = (volatile pgssEntry *) entry;
+
+			SpinLockAcquire(&e->mutex);
+			tmp = e->counters;
+			SpinLockRelease(&e->mutex);
+		}
+
+		values[i++] = Int64GetDatumFast(tmp.calls);
+		values[i++] = Float8GetDatumFast(tmp.total_time);
+		values[i++] = Int64GetDatumFast(tmp.rows);
+		values[i++] = Int64GetDatumFast(tmp.shared_blks_hit);
+		values[i++] = Int64GetDatumFast(tmp.shared_blks_read);
+		values[i++] = Int64GetDatumFast(tmp.shared_blks_written);
+		values[i++] = Int64GetDatumFast(tmp.local_blks_hit);
+		values[i++] = Int64GetDatumFast(tmp.local_blks_read);
+		values[i++] = Int64GetDatumFast(tmp.local_blks_written);
+		values[i++] = Int64GetDatumFast(tmp.temp_blks_read);
+		values[i++] = Int64GetDatumFast(tmp.temp_blks_written);
+
+		Assert(i == PG_STAT_STATEMENTS_COLS);
+
+		tuplestore_putvalues(tupstore, tupdesc, values, nulls);
+	}
+
+	LWLockRelease(pgss->lock);
+
+	/* clean up and return the tuplestore */
+	tuplestore_donestoring(tupstore);
+
+	return (Datum) 0;
+}
+
+/*
+ * Estimate shared memory space needed.
+ */
+static Size
+pgss_memsize(void)
+{
+	Size		size;
+	Size		entrysize;
+
+	size = MAXALIGN(sizeof(pgssSharedState));
+	entrysize = offsetof(pgssEntry, query) +pgstat_track_activity_query_size;
+	size = add_size(size, hash_estimate_size(pgss_max, entrysize));
+
+	return size;
+}
+
+/*
+ * Allocate a new hashtable entry.
+ * caller must hold an exclusive lock on pgss->lock
+ *
+ * Note: despite needing exclusive lock, it's not an error for the target
+ * entry to already exist.	This is because pgss_store releases and
+ * reacquires lock after failing to find a match; so someone else could
+ * have made the entry while we waited to get exclusive lock.
+ */
+static pgssEntry *
+entry_alloc(pgssHashKey *key)
+{
+	pgssEntry  *entry;
+	bool		found;
+
+	/* Caller must have clipped query properly */
+	Assert(key->query_len < pgss->query_size);
+
+	/* Make space if needed */
+	while (hash_get_num_entries(pgss_hash) >= pgss_max)
+		entry_dealloc();
+
+	/* Find or create an entry with desired hash code */
+	entry = (pgssEntry *) hash_search(pgss_hash, key, HASH_ENTER, &found);
+
+	if (!found)
+	{
+		/* New entry, initialize it */
+
+		/* dynahash tried to copy the key for us, but must fix query_ptr */
+		entry->key.query_ptr = entry->query;
+		/* reset the statistics */
+		memset(&entry->counters, 0, sizeof(Counters));
+		entry->counters.usage = USAGE_INIT;
+		/* re-initialize the mutex each time ... we assume no one using it */
+		SpinLockInit(&entry->mutex);
+		/* ... and don't forget the query text */
+		memcpy(entry->query, key->query_ptr, key->query_len);
+		entry->query[key->query_len] = '\0';
+	}
+
+	return entry;
+}
+
+/*
+ * qsort comparator for sorting into increasing usage order
+ */
+static int
+entry_cmp(const void *lhs, const void *rhs)
+{
+	double		l_usage = (*(const pgssEntry **) lhs)->counters.usage;
+	double		r_usage = (*(const pgssEntry **) rhs)->counters.usage;
+
+	if (l_usage < r_usage)
+		return -1;
+	else if (l_usage > r_usage)
+		return +1;
+	else
+		return 0;
+}
+
+/*
+ * Deallocate least used entries.
+ * Caller must hold an exclusive lock on pgss->lock.
+ */
+static void
+entry_dealloc(void)
+{
+	HASH_SEQ_STATUS hash_seq;
+	pgssEntry **entries;
+	pgssEntry  *entry;
+	int			nvictims;
+	int			i;
+
+	/* Sort entries by usage and deallocate USAGE_DEALLOC_PERCENT of them. */
+
+	entries = palloc(hash_get_num_entries(pgss_hash) * sizeof(pgssEntry *));
+
+	i = 0;
+	hash_seq_init(&hash_seq, pgss_hash);
+	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	{
+		entries[i++] = entry;
+		entry->counters.usage *= USAGE_DECREASE_FACTOR;
+	}
+
+	qsort(entries, i, sizeof(pgssEntry *), entry_cmp);
+	nvictims = Max(10, i * USAGE_DEALLOC_PERCENT / 100);
+	nvictims = Min(nvictims, i);
+
+	for (i = 0; i < nvictims; i++)
+	{
+		hash_search(pgss_hash, &entries[i]->key, HASH_REMOVE, NULL);
+	}
+
+	pfree(entries);
+}
+
+/*
+ * Release all entries.
+ */
+static void
+entry_reset(void)
+{
+	HASH_SEQ_STATUS hash_seq;
+	pgssEntry  *entry;
+
+	LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
+
+	hash_seq_init(&hash_seq, pgss_hash);
+	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	{
+		hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
+	}
+
+	LWLockRelease(pgss->lock);
+}
diff --git a/src/extension/pg_stat_statements/pg_stat_statements.control b/src/extension/pg_stat_statements/pg_stat_statements.control
new file mode 100644
index 0000000..6f9a947
--- /dev/null
+++ b/src/extension/pg_stat_statements/pg_stat_statements.control
@@ -0,0 +1,5 @@
+# pg_stat_statements extension
+comment = 'track execution statistics of all SQL statements executed'
+default_version = '1.0'
+module_pathname = '$libdir/pg_stat_statements'
+relocatable = true
diff --git a/src/extension/pgrowlocks/Makefile b/src/extension/pgrowlocks/Makefile
new file mode 100644
index 0000000..a4191fb
--- /dev/null
+++ b/src/extension/pgrowlocks/Makefile
@@ -0,0 +1,19 @@
+# contrib/pgrowlocks/Makefile
+
+MODULE_big	= pgrowlocks
+OBJS		= pgrowlocks.o
+MODULEDIR   = extension
+
+EXTENSION = pgrowlocks
+DATA = pgrowlocks--1.0.sql pgrowlocks--unpackaged--1.0.sql
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/extension/pgrowlocks
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/src/extension/extension-global.mk
+endif
diff --git a/src/extension/pgrowlocks/pgrowlocks--1.0.sql b/src/extension/pgrowlocks/pgrowlocks--1.0.sql
new file mode 100644
index 0000000..0b60fdc
--- /dev/null
+++ b/src/extension/pgrowlocks/pgrowlocks--1.0.sql
@@ -0,0 +1,12 @@
+/* contrib/pgrowlocks/pgrowlocks--1.0.sql */
+
+CREATE FUNCTION pgrowlocks(IN relname text,
+    OUT locked_row TID,		-- row TID
+    OUT lock_type TEXT,		-- lock type
+    OUT locker XID,		-- locking XID
+    OUT multi bool,		-- multi XID?
+    OUT xids xid[],		-- multi XIDs
+    OUT pids INTEGER[])		-- locker's process id
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'pgrowlocks'
+LANGUAGE C STRICT;
diff --git a/src/extension/pgrowlocks/pgrowlocks--unpackaged--1.0.sql b/src/extension/pgrowlocks/pgrowlocks--unpackaged--1.0.sql
new file mode 100644
index 0000000..90d7088
--- /dev/null
+++ b/src/extension/pgrowlocks/pgrowlocks--unpackaged--1.0.sql
@@ -0,0 +1,3 @@
+/* src/extension/pgrowlocks/pgrowlocks--unpackaged--1.0.sql */
+
+ALTER EXTENSION pgrowlocks ADD function pgrowlocks(text);
diff --git a/src/extension/pgrowlocks/pgrowlocks.c b/src/extension/pgrowlocks/pgrowlocks.c
new file mode 100644
index 0000000..aa41491
--- /dev/null
+++ b/src/extension/pgrowlocks/pgrowlocks.c
@@ -0,0 +1,220 @@
+/*
+ * src/extension/pgrowlocks/pgrowlocks.c
+ *
+ * Copyright (c) 2005-2006	Tatsuo Ishii
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose, without fee, and without a
+ * written agreement is hereby granted, provided that the above
+ * copyright notice and this paragraph and the following two
+ * paragraphs appear in all copies.
+ *
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
+ * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
+ * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
+ * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "access/multixact.h"
+#include "access/relscan.h"
+#include "access/xact.h"
+#include "catalog/namespace.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "storage/bufmgr.h"
+#include "storage/procarray.h"
+#include "utils/acl.h"
+#include "utils/builtins.h"
+#include "utils/tqual.h"
+
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(pgrowlocks);
+
+extern Datum pgrowlocks(PG_FUNCTION_ARGS);
+
+/* ----------
+ * pgrowlocks:
+ * returns tids of rows being locked
+ * ----------
+ */
+
+#define NCHARS 32
+
+typedef struct
+{
+	Relation	rel;
+	HeapScanDesc scan;
+	int			ncolumns;
+} MyData;
+
+Datum
+pgrowlocks(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	HeapScanDesc scan;
+	HeapTuple	tuple;
+	TupleDesc	tupdesc;
+	AttInMetadata *attinmeta;
+	Datum		result;
+	MyData	   *mydata;
+	Relation	rel;
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		text	   *relname;
+		RangeVar   *relrv;
+		MemoryContext oldcontext;
+		AclResult	aclresult;
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		/* Build a tuple descriptor for our result type */
+		if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+			elog(ERROR, "return type must be a row type");
+
+		attinmeta = TupleDescGetAttInMetadata(tupdesc);
+		funcctx->attinmeta = attinmeta;
+
+		relname = PG_GETARG_TEXT_P(0);
+		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+		rel = heap_openrv(relrv, AccessShareLock);
+
+		/* check permissions: must have SELECT on table */
+		aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
+									  ACL_SELECT);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, ACL_KIND_CLASS,
+						   RelationGetRelationName(rel));
+
+		scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
+		mydata = palloc(sizeof(*mydata));
+		mydata->rel = rel;
+		mydata->scan = scan;
+		mydata->ncolumns = tupdesc->natts;
+		funcctx->user_fctx = mydata;
+
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	attinmeta = funcctx->attinmeta;
+	mydata = (MyData *) funcctx->user_fctx;
+	scan = mydata->scan;
+
+	/* scan the relation */
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+	{
+		/* must hold a buffer lock to call HeapTupleSatisfiesUpdate */
+		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
+
+		if (HeapTupleSatisfiesUpdate(tuple->t_data,
+									 GetCurrentCommandId(false),
+									 scan->rs_cbuf) == HeapTupleBeingUpdated)
+		{
+
+			char	  **values;
+			int			i;
+
+			values = (char **) palloc(mydata->ncolumns * sizeof(char *));
+
+			i = 0;
+			values[i++] = (char *) DirectFunctionCall1(tidout, PointerGetDatum(&tuple->t_self));
+
+			if (tuple->t_data->t_infomask & HEAP_XMAX_SHARED_LOCK)
+				values[i++] = pstrdup("Shared");
+			else
+				values[i++] = pstrdup("Exclusive");
+			values[i] = palloc(NCHARS * sizeof(char));
+			snprintf(values[i++], NCHARS, "%d", HeapTupleHeaderGetXmax(tuple->t_data));
+			if (tuple->t_data->t_infomask & HEAP_XMAX_IS_MULTI)
+			{
+				TransactionId *xids;
+				int			nxids;
+				int			j;
+				int			isValidXid = 0;		/* any valid xid ever exists? */
+
+				values[i++] = pstrdup("true");
+				nxids = GetMultiXactIdMembers(HeapTupleHeaderGetXmax(tuple->t_data), &xids);
+				if (nxids == -1)
+				{
+					elog(ERROR, "GetMultiXactIdMembers returns error");
+				}
+
+				values[i] = palloc(NCHARS * nxids);
+				values[i + 1] = palloc(NCHARS * nxids);
+				strcpy(values[i], "{");
+				strcpy(values[i + 1], "{");
+
+				for (j = 0; j < nxids; j++)
+				{
+					char		buf[NCHARS];
+
+					if (TransactionIdIsInProgress(xids[j]))
+					{
+						if (isValidXid)
+						{
+							strcat(values[i], ",");
+							strcat(values[i + 1], ",");
+						}
+						snprintf(buf, NCHARS, "%d", xids[j]);
+						strcat(values[i], buf);
+						snprintf(buf, NCHARS, "%d", BackendXidGetPid(xids[j]));
+						strcat(values[i + 1], buf);
+
+						isValidXid = 1;
+					}
+				}
+
+				strcat(values[i], "}");
+				strcat(values[i + 1], "}");
+				i++;
+			}
+			else
+			{
+				values[i++] = pstrdup("false");
+				values[i] = palloc(NCHARS * sizeof(char));
+				snprintf(values[i++], NCHARS, "{%d}", HeapTupleHeaderGetXmax(tuple->t_data));
+
+				values[i] = palloc(NCHARS * sizeof(char));
+				snprintf(values[i++], NCHARS, "{%d}", BackendXidGetPid(HeapTupleHeaderGetXmax(tuple->t_data)));
+			}
+
+			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
+
+			/* build a tuple */
+			tuple = BuildTupleFromCStrings(attinmeta, values);
+
+			/* make the tuple into a datum */
+			result = HeapTupleGetDatum(tuple);
+
+			/* Clean up */
+			for (i = 0; i < mydata->ncolumns; i++)
+				pfree(values[i]);
+			pfree(values);
+
+			SRF_RETURN_NEXT(funcctx, result);
+		}
+		else
+		{
+			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
+		}
+	}
+
+	heap_endscan(scan);
+	heap_close(mydata->rel, AccessShareLock);
+
+	SRF_RETURN_DONE(funcctx);
+}
diff --git a/src/extension/pgrowlocks/pgrowlocks.control b/src/extension/pgrowlocks/pgrowlocks.control
new file mode 100644
index 0000000..a6ba164
--- /dev/null
+++ b/src/extension/pgrowlocks/pgrowlocks.control
@@ -0,0 +1,5 @@
+# pgrowlocks extension
+comment = 'show row-level locking information'
+default_version = '1.0'
+module_pathname = '$libdir/pgrowlocks'
+relocatable = true
diff --git a/src/extension/pgstattuple/Makefile b/src/extension/pgstattuple/Makefile
new file mode 100644
index 0000000..296ca57
--- /dev/null
+++ b/src/extension/pgstattuple/Makefile
@@ -0,0 +1,19 @@
+# src/extension/pgstattuple/Makefile
+
+MODULE_big	= pgstattuple
+OBJS		= pgstattuple.o pgstatindex.o
+MODULEDIR   = extension
+
+EXTENSION = pgstattuple
+DATA = pgstattuple--1.0.sql pgstattuple--unpackaged--1.0.sql
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/extension/pgstattuple
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/src/extension/extension-global.mk
+endif
diff --git a/src/extension/pgstattuple/pgstatindex.c b/src/extension/pgstattuple/pgstatindex.c
new file mode 100644
index 0000000..77ca208
--- /dev/null
+++ b/src/extension/pgstattuple/pgstatindex.c
@@ -0,0 +1,282 @@
+/*
+ * src/extension/pgstattuple/pgstatindex.c
+ *
+ *
+ * pgstatindex
+ *
+ * Copyright (c) 2006 Satoshi Nagayasu <nagayasus@nttdata.co.jp>
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose, without fee, and without a
+ * written agreement is hereby granted, provided that the above
+ * copyright notice and this paragraph and the following two
+ * paragraphs appear in all copies.
+ *
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
+ * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
+ * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
+ * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "access/nbtree.h"
+#include "catalog/namespace.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "storage/bufmgr.h"
+#include "utils/builtins.h"
+
+
+extern Datum pgstatindex(PG_FUNCTION_ARGS);
+extern Datum pg_relpages(PG_FUNCTION_ARGS);
+
+PG_FUNCTION_INFO_V1(pgstatindex);
+PG_FUNCTION_INFO_V1(pg_relpages);
+
+#define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
+#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
+
+#define CHECK_PAGE_OFFSET_RANGE(pg, offnum) { \
+		if ( !(FirstOffsetNumber <= (offnum) && \
+						(offnum) <= PageGetMaxOffsetNumber(pg)) ) \
+			 elog(ERROR, "page offset number out of range"); }
+
+/* note: BlockNumber is unsigned, hence can't be negative */
+#define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
+		if ( RelationGetNumberOfBlocks(rel) <= (BlockNumber) (blkno) ) \
+			 elog(ERROR, "block number out of range"); }
+
+/* ------------------------------------------------
+ * A structure for a whole btree index statistics
+ * used by pgstatindex().
+ * ------------------------------------------------
+ */
+typedef struct BTIndexStat
+{
+	uint32		version;
+	uint32		level;
+	BlockNumber root_blkno;
+
+	uint64		root_pages;
+	uint64		internal_pages;
+	uint64		leaf_pages;
+	uint64		empty_pages;
+	uint64		deleted_pages;
+
+	uint64		max_avail;
+	uint64		free_space;
+
+	uint64		fragments;
+} BTIndexStat;
+
+/* ------------------------------------------------------
+ * pgstatindex()
+ *
+ * Usage: SELECT * FROM pgstatindex('t1_pkey');
+ * ------------------------------------------------------
+ */
+Datum
+pgstatindex(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	Relation	rel;
+	RangeVar   *relrv;
+	Datum		result;
+	BlockNumber nblocks;
+	BlockNumber blkno;
+	BTIndexStat indexStat;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pgstattuple functions"))));
+
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	if (!IS_INDEX(rel) || !IS_BTREE(rel))
+		elog(ERROR, "relation \"%s\" is not a btree index",
+			 RelationGetRelationName(rel));
+
+	/*
+	 * Reject attempts to read non-local temporary relations; we would be
+	 * likely to get wrong data since we have no visibility into the owning
+	 * session's local buffers.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot access temporary tables of other sessions")));
+
+	/*
+	 * Read metapage
+	 */
+	{
+		Buffer		buffer = ReadBuffer(rel, 0);
+		Page		page = BufferGetPage(buffer);
+		BTMetaPageData *metad = BTPageGetMeta(page);
+
+		indexStat.version = metad->btm_version;
+		indexStat.level = metad->btm_level;
+		indexStat.root_blkno = metad->btm_root;
+
+		ReleaseBuffer(buffer);
+	}
+
+	/* -- init counters -- */
+	indexStat.root_pages = 0;
+	indexStat.internal_pages = 0;
+	indexStat.leaf_pages = 0;
+	indexStat.empty_pages = 0;
+	indexStat.deleted_pages = 0;
+
+	indexStat.max_avail = 0;
+	indexStat.free_space = 0;
+
+	indexStat.fragments = 0;
+
+	/*
+	 * Scan all blocks except the metapage
+	 */
+	nblocks = RelationGetNumberOfBlocks(rel);
+
+	for (blkno = 1; blkno < nblocks; blkno++)
+	{
+		Buffer		buffer;
+		Page		page;
+		BTPageOpaque opaque;
+
+		/* Read and lock buffer */
+		buffer = ReadBuffer(rel, blkno);
+		LockBuffer(buffer, BUFFER_LOCK_SHARE);
+
+		page = BufferGetPage(buffer);
+		opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+
+		/* Determine page type, and update totals */
+
+		if (P_ISLEAF(opaque))
+		{
+			int			max_avail;
+
+			max_avail = BLCKSZ - (BLCKSZ - ((PageHeader) page)->pd_special + SizeOfPageHeaderData);
+			indexStat.max_avail += max_avail;
+			indexStat.free_space += PageGetFreeSpace(page);
+
+			indexStat.leaf_pages++;
+
+			/*
+			 * If the next leaf is on an earlier block, it means a
+			 * fragmentation.
+			 */
+			if (opaque->btpo_next != P_NONE && opaque->btpo_next < blkno)
+				indexStat.fragments++;
+		}
+		else if (P_ISDELETED(opaque))
+			indexStat.deleted_pages++;
+		else if (P_IGNORE(opaque))
+			indexStat.empty_pages++;
+		else if (P_ISROOT(opaque))
+			indexStat.root_pages++;
+		else
+			indexStat.internal_pages++;
+
+		/* Unlock and release buffer */
+		LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
+		ReleaseBuffer(buffer);
+	}
+
+	relation_close(rel, AccessShareLock);
+
+	/*----------------------------
+	 * Build a result tuple
+	 *----------------------------
+	 */
+	{
+		TupleDesc	tupleDesc;
+		int			j;
+		char	   *values[10];
+		HeapTuple	tuple;
+
+		/* Build a tuple descriptor for our result type */
+		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+			elog(ERROR, "return type must be a row type");
+
+		j = 0;
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%d", indexStat.version);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%d", indexStat.level);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, INT64_FORMAT,
+				 (indexStat.root_pages +
+				  indexStat.leaf_pages +
+				  indexStat.internal_pages +
+				  indexStat.deleted_pages +
+				  indexStat.empty_pages) * BLCKSZ);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%u", indexStat.root_blkno);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, INT64_FORMAT, indexStat.internal_pages);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, INT64_FORMAT, indexStat.leaf_pages);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, INT64_FORMAT, indexStat.empty_pages);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, INT64_FORMAT, indexStat.deleted_pages);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%.2f", 100.0 - (double) indexStat.free_space / (double) indexStat.max_avail * 100.0);
+		values[j] = palloc(32);
+		snprintf(values[j++], 32, "%.2f", (double) indexStat.fragments / (double) indexStat.leaf_pages * 100.0);
+
+		tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
+									   values);
+
+		result = HeapTupleGetDatum(tuple);
+	}
+
+	PG_RETURN_DATUM(result);
+}
+
+/* --------------------------------------------------------
+ * pg_relpages()
+ *
+ * Get the number of pages of the table/index.
+ *
+ * Usage: SELECT pg_relpages('t1');
+ *		  SELECT pg_relpages('t1_pkey');
+ * --------------------------------------------------------
+ */
+Datum
+pg_relpages(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	int64		relpages;
+	Relation	rel;
+	RangeVar   *relrv;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pgstattuple functions"))));
+
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	/* note: this will work OK on non-local temp tables */
+
+	relpages = RelationGetNumberOfBlocks(rel);
+
+	relation_close(rel, AccessShareLock);
+
+	PG_RETURN_INT64(relpages);
+}
diff --git a/src/extension/pgstattuple/pgstattuple--1.0.sql b/src/extension/pgstattuple/pgstattuple--1.0.sql
new file mode 100644
index 0000000..7b78905
--- /dev/null
+++ b/src/extension/pgstattuple/pgstattuple--1.0.sql
@@ -0,0 +1,46 @@
+/* src/extension/pgstattuple/pgstattuple--1.0.sql */
+
+CREATE FUNCTION pgstattuple(IN relname text,
+    OUT table_len BIGINT,		-- physical table length in bytes
+    OUT tuple_count BIGINT,		-- number of live tuples
+    OUT tuple_len BIGINT,		-- total tuples length in bytes
+    OUT tuple_percent FLOAT8,		-- live tuples in %
+    OUT dead_tuple_count BIGINT,	-- number of dead tuples
+    OUT dead_tuple_len BIGINT,		-- total dead tuples length in bytes
+    OUT dead_tuple_percent FLOAT8,	-- dead tuples in %
+    OUT free_space BIGINT,		-- free space in bytes
+    OUT free_percent FLOAT8)		-- free space in %
+AS 'MODULE_PATHNAME', 'pgstattuple'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION pgstattuple(IN reloid oid,
+    OUT table_len BIGINT,		-- physical table length in bytes
+    OUT tuple_count BIGINT,		-- number of live tuples
+    OUT tuple_len BIGINT,		-- total tuples length in bytes
+    OUT tuple_percent FLOAT8,		-- live tuples in %
+    OUT dead_tuple_count BIGINT,	-- number of dead tuples
+    OUT dead_tuple_len BIGINT,		-- total dead tuples length in bytes
+    OUT dead_tuple_percent FLOAT8,	-- dead tuples in %
+    OUT free_space BIGINT,		-- free space in bytes
+    OUT free_percent FLOAT8)		-- free space in %
+AS 'MODULE_PATHNAME', 'pgstattuplebyid'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION pgstatindex(IN relname text,
+    OUT version INT,
+    OUT tree_level INT,
+    OUT index_size BIGINT,
+    OUT root_block_no BIGINT,
+    OUT internal_pages BIGINT,
+    OUT leaf_pages BIGINT,
+    OUT empty_pages BIGINT,
+    OUT deleted_pages BIGINT,
+    OUT avg_leaf_density FLOAT8,
+    OUT leaf_fragmentation FLOAT8)
+AS 'MODULE_PATHNAME', 'pgstatindex'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION pg_relpages(IN relname text)
+RETURNS BIGINT
+AS 'MODULE_PATHNAME', 'pg_relpages'
+LANGUAGE C STRICT;
diff --git a/src/extension/pgstattuple/pgstattuple--unpackaged--1.0.sql b/src/extension/pgstattuple/pgstattuple--unpackaged--1.0.sql
new file mode 100644
index 0000000..6a1474a
--- /dev/null
+++ b/src/extension/pgstattuple/pgstattuple--unpackaged--1.0.sql
@@ -0,0 +1,6 @@
+/* src/extension/pgstattuple/pgstattuple--unpackaged--1.0.sql */
+
+ALTER EXTENSION pgstattuple ADD function pgstattuple(text);
+ALTER EXTENSION pgstattuple ADD function pgstattuple(oid);
+ALTER EXTENSION pgstattuple ADD function pgstatindex(text);
+ALTER EXTENSION pgstattuple ADD function pg_relpages(text);
diff --git a/src/extension/pgstattuple/pgstattuple.c b/src/extension/pgstattuple/pgstattuple.c
new file mode 100644
index 0000000..76357ee
--- /dev/null
+++ b/src/extension/pgstattuple/pgstattuple.c
@@ -0,0 +1,518 @@
+/*
+ * src/extension/pgstattuple/pgstattuple.c
+ *
+ * Copyright (c) 2001,2002	Tatsuo Ishii
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose, without fee, and without a
+ * written agreement is hereby granted, provided that the above
+ * copyright notice and this paragraph and the following two
+ * paragraphs appear in all copies.
+ *
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
+ * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
+ * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
+ * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#include "postgres.h"
+
+#include "access/gist_private.h"
+#include "access/hash.h"
+#include "access/nbtree.h"
+#include "access/relscan.h"
+#include "catalog/namespace.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "storage/bufmgr.h"
+#include "storage/lmgr.h"
+#include "utils/builtins.h"
+#include "utils/tqual.h"
+
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(pgstattuple);
+PG_FUNCTION_INFO_V1(pgstattuplebyid);
+
+extern Datum pgstattuple(PG_FUNCTION_ARGS);
+extern Datum pgstattuplebyid(PG_FUNCTION_ARGS);
+
+/*
+ * struct pgstattuple_type
+ *
+ * tuple_percent, dead_tuple_percent and free_percent are computable,
+ * so not defined here.
+ */
+typedef struct pgstattuple_type
+{
+	uint64		table_len;
+	uint64		tuple_count;
+	uint64		tuple_len;
+	uint64		dead_tuple_count;
+	uint64		dead_tuple_len;
+	uint64		free_space;		/* free/reusable space in bytes */
+} pgstattuple_type;
+
+typedef void (*pgstat_page) (pgstattuple_type *, Relation, BlockNumber);
+
+static Datum build_pgstattuple_type(pgstattuple_type *stat,
+					   FunctionCallInfo fcinfo);
+static Datum pgstat_relation(Relation rel, FunctionCallInfo fcinfo);
+static Datum pgstat_heap(Relation rel, FunctionCallInfo fcinfo);
+static void pgstat_btree_page(pgstattuple_type *stat,
+				  Relation rel, BlockNumber blkno);
+static void pgstat_hash_page(pgstattuple_type *stat,
+				 Relation rel, BlockNumber blkno);
+static void pgstat_gist_page(pgstattuple_type *stat,
+				 Relation rel, BlockNumber blkno);
+static Datum pgstat_index(Relation rel, BlockNumber start,
+			 pgstat_page pagefn, FunctionCallInfo fcinfo);
+static void pgstat_index_page(pgstattuple_type *stat, Page page,
+				  OffsetNumber minoff, OffsetNumber maxoff);
+
+/*
+ * build_pgstattuple_type -- build a pgstattuple_type tuple
+ */
+static Datum
+build_pgstattuple_type(pgstattuple_type *stat, FunctionCallInfo fcinfo)
+{
+#define NCOLUMNS	9
+#define NCHARS		32
+
+	HeapTuple	tuple;
+	char	   *values[NCOLUMNS];
+	char		values_buf[NCOLUMNS][NCHARS];
+	int			i;
+	double		tuple_percent;
+	double		dead_tuple_percent;
+	double		free_percent;	/* free/reusable space in % */
+	TupleDesc	tupdesc;
+	AttInMetadata *attinmeta;
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	/*
+	 * Generate attribute metadata needed later to produce tuples from raw C
+	 * strings
+	 */
+	attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+	if (stat->table_len == 0)
+	{
+		tuple_percent = 0.0;
+		dead_tuple_percent = 0.0;
+		free_percent = 0.0;
+	}
+	else
+	{
+		tuple_percent = 100.0 * stat->tuple_len / stat->table_len;
+		dead_tuple_percent = 100.0 * stat->dead_tuple_len / stat->table_len;
+		free_percent = 100.0 * stat->free_space / stat->table_len;
+	}
+
+	/*
+	 * Prepare a values array for constructing the tuple. This should be an
+	 * array of C strings which will be processed later by the appropriate
+	 * "in" functions.
+	 */
+	for (i = 0; i < NCOLUMNS; i++)
+		values[i] = values_buf[i];
+	i = 0;
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->table_len);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->tuple_count);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->tuple_len);
+	snprintf(values[i++], NCHARS, "%.2f", tuple_percent);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->dead_tuple_count);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->dead_tuple_len);
+	snprintf(values[i++], NCHARS, "%.2f", dead_tuple_percent);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->free_space);
+	snprintf(values[i++], NCHARS, "%.2f", free_percent);
+
+	/* build a tuple */
+	tuple = BuildTupleFromCStrings(attinmeta, values);
+
+	/* make the tuple into a datum */
+	return HeapTupleGetDatum(tuple);
+}
+
+/* ----------
+ * pgstattuple:
+ * returns live/dead tuples info
+ *
+ * C FUNCTION definition
+ * pgstattuple(text) returns pgstattuple_type
+ * see pgstattuple.sql for pgstattuple_type
+ * ----------
+ */
+
+Datum
+pgstattuple(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_P(0);
+	RangeVar   *relrv;
+	Relation	rel;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pgstattuple functions"))));
+
+	/* open relation */
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
+}
+
+Datum
+pgstattuplebyid(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	Relation	rel;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pgstattuple functions"))));
+
+	/* open relation */
+	rel = relation_open(relid, AccessShareLock);
+
+	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
+}
+
+/*
+ * pgstat_relation
+ */
+static Datum
+pgstat_relation(Relation rel, FunctionCallInfo fcinfo)
+{
+	const char *err;
+
+	/*
+	 * Reject attempts to read non-local temporary relations; we would be
+	 * likely to get wrong data since we have no visibility into the owning
+	 * session's local buffers.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot access temporary tables of other sessions")));
+
+	switch (rel->rd_rel->relkind)
+	{
+		case RELKIND_RELATION:
+		case RELKIND_TOASTVALUE:
+		case RELKIND_UNCATALOGED:
+		case RELKIND_SEQUENCE:
+			return pgstat_heap(rel, fcinfo);
+		case RELKIND_INDEX:
+			switch (rel->rd_rel->relam)
+			{
+				case BTREE_AM_OID:
+					return pgstat_index(rel, BTREE_METAPAGE + 1,
+										pgstat_btree_page, fcinfo);
+				case HASH_AM_OID:
+					return pgstat_index(rel, HASH_METAPAGE + 1,
+										pgstat_hash_page, fcinfo);
+				case GIST_AM_OID:
+					return pgstat_index(rel, GIST_ROOT_BLKNO + 1,
+										pgstat_gist_page, fcinfo);
+				case GIN_AM_OID:
+					err = "gin index";
+					break;
+				default:
+					err = "unknown index";
+					break;
+			}
+			break;
+		case RELKIND_VIEW:
+			err = "view";
+			break;
+		case RELKIND_COMPOSITE_TYPE:
+			err = "composite type";
+			break;
+		case RELKIND_FOREIGN_TABLE:
+			err = "foreign table";
+			break;
+		default:
+			err = "unknown";
+			break;
+	}
+
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("\"%s\" (%s) is not supported",
+					RelationGetRelationName(rel), err)));
+	return 0;					/* should not happen */
+}
+
+/*
+ * pgstat_heap -- returns live/dead tuples info in a heap
+ */
+static Datum
+pgstat_heap(Relation rel, FunctionCallInfo fcinfo)
+{
+	HeapScanDesc scan;
+	HeapTuple	tuple;
+	BlockNumber nblocks;
+	BlockNumber block = 0;		/* next block to count free space in */
+	BlockNumber tupblock;
+	Buffer		buffer;
+	pgstattuple_type stat = {0};
+
+	/* Disable syncscan because we assume we scan from block zero upwards */
+	scan = heap_beginscan_strat(rel, SnapshotAny, 0, NULL, true, false);
+
+	nblocks = scan->rs_nblocks; /* # blocks to be scanned */
+
+	/* scan the relation */
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+	{
+		CHECK_FOR_INTERRUPTS();
+
+		/* must hold a buffer lock to call HeapTupleSatisfiesVisibility */
+		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
+
+		if (HeapTupleSatisfiesVisibility(tuple, SnapshotNow, scan->rs_cbuf))
+		{
+			stat.tuple_len += tuple->t_len;
+			stat.tuple_count++;
+		}
+		else
+		{
+			stat.dead_tuple_len += tuple->t_len;
+			stat.dead_tuple_count++;
+		}
+
+		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
+
+		/*
+		 * To avoid physically reading the table twice, try to do the
+		 * free-space scan in parallel with the heap scan.	However,
+		 * heap_getnext may find no tuples on a given page, so we cannot
+		 * simply examine the pages returned by the heap scan.
+		 */
+		tupblock = BlockIdGetBlockNumber(&tuple->t_self.ip_blkid);
+
+		while (block <= tupblock)
+		{
+			CHECK_FOR_INTERRUPTS();
+
+			buffer = ReadBuffer(rel, block);
+			LockBuffer(buffer, BUFFER_LOCK_SHARE);
+			stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
+			UnlockReleaseBuffer(buffer);
+			block++;
+		}
+	}
+	heap_endscan(scan);
+
+	while (block < nblocks)
+	{
+		CHECK_FOR_INTERRUPTS();
+
+		buffer = ReadBuffer(rel, block);
+		LockBuffer(buffer, BUFFER_LOCK_SHARE);
+		stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
+		UnlockReleaseBuffer(buffer);
+		block++;
+	}
+
+	relation_close(rel, AccessShareLock);
+
+	stat.table_len = (uint64) nblocks *BLCKSZ;
+
+	return build_pgstattuple_type(&stat, fcinfo);
+}
+
+/*
+ * pgstat_btree_page -- check tuples in a btree page
+ */
+static void
+pgstat_btree_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno)
+{
+	Buffer		buf;
+	Page		page;
+
+	buf = ReadBuffer(rel, blkno);
+	LockBuffer(buf, BT_READ);
+	page = BufferGetPage(buf);
+
+	/* Page is valid, see what to do with it */
+	if (PageIsNew(page))
+	{
+		/* fully empty page */
+		stat->free_space += BLCKSZ;
+	}
+	else
+	{
+		BTPageOpaque opaque;
+
+		opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+		if (opaque->btpo_flags & (BTP_DELETED | BTP_HALF_DEAD))
+		{
+			/* recyclable page */
+			stat->free_space += BLCKSZ;
+		}
+		else if (P_ISLEAF(opaque))
+		{
+			pgstat_index_page(stat, page, P_FIRSTDATAKEY(opaque),
+							  PageGetMaxOffsetNumber(page));
+		}
+		else
+		{
+			/* root or node */
+		}
+	}
+
+	_bt_relbuf(rel, buf);
+}
+
+/*
+ * pgstat_hash_page -- check tuples in a hash page
+ */
+static void
+pgstat_hash_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno)
+{
+	Buffer		buf;
+	Page		page;
+
+	_hash_getlock(rel, blkno, HASH_SHARE);
+	buf = _hash_getbuf(rel, blkno, HASH_READ, 0);
+	page = BufferGetPage(buf);
+
+	if (PageGetSpecialSize(page) == MAXALIGN(sizeof(HashPageOpaqueData)))
+	{
+		HashPageOpaque opaque;
+
+		opaque = (HashPageOpaque) PageGetSpecialPointer(page);
+		switch (opaque->hasho_flag)
+		{
+			case LH_UNUSED_PAGE:
+				stat->free_space += BLCKSZ;
+				break;
+			case LH_BUCKET_PAGE:
+			case LH_OVERFLOW_PAGE:
+				pgstat_index_page(stat, page, FirstOffsetNumber,
+								  PageGetMaxOffsetNumber(page));
+				break;
+			case LH_BITMAP_PAGE:
+			case LH_META_PAGE:
+			default:
+				break;
+		}
+	}
+	else
+	{
+		/* maybe corrupted */
+	}
+
+	_hash_relbuf(rel, buf);
+	_hash_droplock(rel, blkno, HASH_SHARE);
+}
+
+/*
+ * pgstat_gist_page -- check tuples in a gist page
+ */
+static void
+pgstat_gist_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno)
+{
+	Buffer		buf;
+	Page		page;
+
+	buf = ReadBuffer(rel, blkno);
+	LockBuffer(buf, GIST_SHARE);
+	gistcheckpage(rel, buf);
+	page = BufferGetPage(buf);
+
+	if (GistPageIsLeaf(page))
+	{
+		pgstat_index_page(stat, page, FirstOffsetNumber,
+						  PageGetMaxOffsetNumber(page));
+	}
+	else
+	{
+		/* root or node */
+	}
+
+	UnlockReleaseBuffer(buf);
+}
+
+/*
+ * pgstat_index -- returns live/dead tuples info in a generic index
+ */
+static Datum
+pgstat_index(Relation rel, BlockNumber start, pgstat_page pagefn,
+			 FunctionCallInfo fcinfo)
+{
+	BlockNumber nblocks;
+	BlockNumber blkno;
+	pgstattuple_type stat = {0};
+
+	blkno = start;
+	for (;;)
+	{
+		/* Get the current relation length */
+		LockRelationForExtension(rel, ExclusiveLock);
+		nblocks = RelationGetNumberOfBlocks(rel);
+		UnlockRelationForExtension(rel, ExclusiveLock);
+
+		/* Quit if we've scanned the whole relation */
+		if (blkno >= nblocks)
+		{
+			stat.table_len = (uint64) nblocks *BLCKSZ;
+
+			break;
+		}
+
+		for (; blkno < nblocks; blkno++)
+		{
+			CHECK_FOR_INTERRUPTS();
+
+			pagefn(&stat, rel, blkno);
+		}
+	}
+
+	relation_close(rel, AccessShareLock);
+
+	return build_pgstattuple_type(&stat, fcinfo);
+}
+
+/*
+ * pgstat_index_page -- for generic index page
+ */
+static void
+pgstat_index_page(pgstattuple_type *stat, Page page,
+				  OffsetNumber minoff, OffsetNumber maxoff)
+{
+	OffsetNumber i;
+
+	stat->free_space += PageGetFreeSpace(page);
+
+	for (i = minoff; i <= maxoff; i = OffsetNumberNext(i))
+	{
+		ItemId		itemid = PageGetItemId(page, i);
+
+		if (ItemIdIsDead(itemid))
+		{
+			stat->dead_tuple_count++;
+			stat->dead_tuple_len += ItemIdGetLength(itemid);
+		}
+		else
+		{
+			stat->tuple_count++;
+			stat->tuple_len += ItemIdGetLength(itemid);
+		}
+	}
+}
diff --git a/src/extension/pgstattuple/pgstattuple.control b/src/extension/pgstattuple/pgstattuple.control
new file mode 100644
index 0000000..7b5129b
--- /dev/null
+++ b/src/extension/pgstattuple/pgstattuple.control
@@ -0,0 +1,5 @@
+# pgstattuple extension
+comment = 'show tuple-level statistics'
+default_version = '1.0'
+module_pathname = '$libdir/pgstattuple'
+relocatable = true