global_temporary_table_v17-pg13.patch

diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index c3d45c7..3f9e875 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -168,6 +168,19 @@ static relopt_bool boolRelOpts[] =
 		},
 		true
 	},
+	/*
+	 * For global temp table only
+	 * use ShareUpdateExclusiveLock for ensure safety
+	 */
+	{
+		{
+			"on_commit_delete_rows",
+			"global temp table on commit options",
+			RELOPT_KIND_HEAP | RELOPT_KIND_PARTITIONED,
+			ShareUpdateExclusiveLock
+		},
+		true
+	},	
 	/* list terminator */
 	{{NULL}}
 };
@@ -1496,6 +1509,8 @@ bytea *
 default_reloptions(Datum reloptions, bool validate, relopt_kind kind)
 {
 	static const relopt_parse_elt tab[] = {
+		{"on_commit_delete_rows", RELOPT_TYPE_BOOL,
+		offsetof(StdRdOptions, on_commit_delete_rows)},
 		{"fillfactor", RELOPT_TYPE_INT, offsetof(StdRdOptions, fillfactor)},
 		{"autovacuum_enabled", RELOPT_TYPE_BOOL,
 		offsetof(StdRdOptions, autovacuum) + offsetof(AutoVacOpts, enabled)},
@@ -1596,13 +1611,18 @@ build_reloptions(Datum reloptions, bool validate,
 bytea *
 partitioned_table_reloptions(Datum reloptions, bool validate)
 {
+	static const relopt_parse_elt tab[] = {
+		{"on_commit_delete_rows", RELOPT_TYPE_BOOL,
+		offsetof(StdRdOptions, on_commit_delete_rows)}
+	};
+
 	/*
 	 * There are no options for partitioned tables yet, but this is able to do
 	 * some validation.
 	 */
 	return (bytea *) build_reloptions(reloptions, validate,
 									  RELOPT_KIND_PARTITIONED,
-									  0, NULL, 0);
+									  sizeof(StdRdOptions), tab, lengthof(tab));
 }
 
 /*
diff --git a/src/backend/access/gist/gistutil.c b/src/backend/access/gist/gistutil.c
index dd975b1..1610e7d 100644
--- a/src/backend/access/gist/gistutil.c
+++ b/src/backend/access/gist/gistutil.c
@@ -1013,7 +1013,9 @@ gistGetFakeLSN(Relation rel)
 {
 	static XLogRecPtr counter = FirstNormalUnloggedLSN;
 
-	if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+	/* global temp is same as local temp table */
+	if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP ||
+		rel->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 	{
 		/*
 		 * Temporary relations are only accessible in our session, so a simple
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index 4871b7f..16b00c9 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -149,7 +149,9 @@ hashbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 	 * metapage, nor the first bitmap page.
 	 */
 	sort_threshold = (maintenance_work_mem * 1024L) / BLCKSZ;
-	if (index->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
+	/* global temp table is same as local temp table */
+	if (!(index->rd_rel->relpersistence == RELPERSISTENCE_TEMP ||
+		index->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP))
 		sort_threshold = Min(sort_threshold, NBuffers);
 	else
 		sort_threshold = Min(sort_threshold, NLocBuffer);
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index ca52846..f0153cf 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -598,7 +598,7 @@ heapam_relation_set_new_filenode(Relation rel,
 	 */
 	*minmulti = GetOldestMultiXactId();
 
-	srel = RelationCreateStorage(*newrnode, persistence);
+	srel = RelationCreateStorage(*newrnode, persistence, rel);
 
 	/*
 	 * If required, set up an init fork for an unlogged table so that it can
@@ -651,7 +651,7 @@ heapam_relation_copy_data(Relation rel, const RelFileNode *newrnode)
 	 * NOTE: any conflict in relfilenode value will be caught in
 	 * RelationCreateStorage().
 	 */
-	RelationCreateStorage(*newrnode, rel->rd_rel->relpersistence);
+	RelationCreateStorage(*newrnode, rel->rd_rel->relpersistence, rel);
 
 	/* copy main fork */
 	RelationCopyStorage(rel->rd_smgr, dstrel, MAIN_FORKNUM,
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 03c43ef..2674132 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -62,6 +62,7 @@
 #include "access/xact.h"
 #include "access/xlog.h"
 #include "catalog/storage.h"
+#include "catalog/storage_gtt.h"
 #include "commands/dbcommands.h"
 #include "commands/progress.h"
 #include "commands/vacuum.h"
@@ -399,9 +400,9 @@ heap_vacuum_rel(Relation onerel, VacuumParams *params,
 	Assert(params->index_cleanup != VACOPT_TERNARY_DEFAULT);
 	Assert(params->truncate != VACOPT_TERNARY_DEFAULT);
 
-	/* not every AM requires these to be valid, but heap does */
-	Assert(TransactionIdIsNormal(onerel->rd_rel->relfrozenxid));
-	Assert(MultiXactIdIsValid(onerel->rd_rel->relminmxid));
+	/* not every AM requires these to be valid, but regular heap does */
+	Assert(RELATION_IS_GLOBAL_TEMP(onerel) ^ TransactionIdIsNormal(onerel->rd_rel->relfrozenxid));
+	Assert(RELATION_IS_GLOBAL_TEMP(onerel) ^ MultiXactIdIsValid(onerel->rd_rel->relminmxid));
 
 	/* measure elapsed time iff autovacuum logging requires it */
 	if (IsAutoVacuumWorkerProcess() && params->log_min_duration >= 0)
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index 39b8f17..38b46d0 100644
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -28,6 +28,7 @@
 #include "access/transam.h"
 #include "access/xlog.h"
 #include "access/xloginsert.h"
+#include "catalog/storage_gtt.h"
 #include "miscadmin.h"
 #include "storage/indexfsm.h"
 #include "storage/lmgr.h"
@@ -601,6 +602,10 @@ _bt_getrootheight(Relation rel)
 	{
 		Buffer		metabuf;
 
+		if (RELATION_IS_GLOBAL_TEMP(rel) &&
+			!gtt_storage_attached(rel->rd_node.relNode))
+			return 0;
+
 		metabuf = _bt_getbuf(rel, BTREE_METAPAGE, BT_READ);
 		metad = _bt_getmeta(rel, metabuf);
 
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 4361568..08ef041 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -6348,6 +6348,10 @@ StartupXLOG(void)
 	else
 		recoveryTargetTLI = ControlFile->checkPointCopy.ThisTimeLineID;
 
+	/* clean temp relation files */
+	if (max_active_gtt > 0)
+		RemovePgTempFiles();
+
 	/*
 	 * Check for signal files, and if so set up state for offline recovery
 	 */
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index f8f0b48..dc8bbb1 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -42,6 +42,7 @@ OBJS = \
 	pg_subscription.o \
 	pg_type.o \
 	storage.o \
+	storage_gtt.o \
 	toasting.o
 
 include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index 7d6acae..3be8d63 100644
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -393,7 +393,9 @@ GetNewRelFileNode(Oid reltablespace, Relation pg_class, char relpersistence)
 
 	switch (relpersistence)
 	{
+		/* global temp table is same as local temp table */
 		case RELPERSISTENCE_TEMP:
+		case RELPERSISTENCE_GLOBAL_TEMP:
 			backend = BackendIdForTempRelations();
 			break;
 		case RELPERSISTENCE_UNLOGGED:
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 9d9e915..1c50263 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -61,6 +61,7 @@
 #include "catalog/pg_type.h"
 #include "catalog/storage.h"
 #include "catalog/storage_xlog.h"
+#include "catalog/storage_gtt.h"
 #include "commands/tablecmds.h"
 #include "commands/typecmds.h"
 #include "executor/executor.h"
@@ -99,6 +100,7 @@ static void AddNewRelationTuple(Relation pg_class_desc,
 								Oid reloftype,
 								Oid relowner,
 								char relkind,
+								char relpersistence,
 								TransactionId relfrozenxid,
 								TransactionId relminmxid,
 								Datum relacl,
@@ -427,7 +429,7 @@ heap_create(const char *relname,
 
 			case RELKIND_INDEX:
 			case RELKIND_SEQUENCE:
-				RelationCreateStorage(rel->rd_node, relpersistence);
+				RelationCreateStorage(rel->rd_node, relpersistence, rel);
 				break;
 
 			case RELKIND_RELATION:
@@ -957,6 +959,7 @@ AddNewRelationTuple(Relation pg_class_desc,
 					Oid reloftype,
 					Oid relowner,
 					char relkind,
+					char relpersistence,
 					TransactionId relfrozenxid,
 					TransactionId relminmxid,
 					Datum relacl,
@@ -995,8 +998,18 @@ AddNewRelationTuple(Relation pg_class_desc,
 			break;
 	}
 
-	new_rel_reltup->relfrozenxid = relfrozenxid;
-	new_rel_reltup->relminmxid = relminmxid;
+	/* global temp table not remember transaction info in catalog */
+	if (relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+	{
+		new_rel_reltup->relfrozenxid = InvalidTransactionId;
+		new_rel_reltup->relminmxid = InvalidMultiXactId;
+	}
+	else
+	{
+		new_rel_reltup->relfrozenxid = relfrozenxid;
+		new_rel_reltup->relminmxid = relminmxid;
+	}
+
 	new_rel_reltup->relowner = relowner;
 	new_rel_reltup->reltype = new_type_oid;
 	new_rel_reltup->reloftype = reloftype;
@@ -1358,6 +1371,7 @@ heap_create_with_catalog(const char *relname,
 						reloftypeid,
 						ownerid,
 						relkind,
+						relpersistence,
 						relfrozenxid,
 						relminmxid,
 						PointerGetDatum(relacl),
@@ -1938,6 +1952,14 @@ heap_drop_with_catalog(Oid relid)
 	if (relid == defaultPartOid)
 		update_default_partition_oid(parentOid, InvalidOid);
 
+	/* We allow to drop global temp table only this session use it */
+	if (RELATION_IS_GLOBAL_TEMP(rel))
+	{
+		if (is_other_backend_use_gtt(rel->rd_node))
+			elog(ERROR, "can not drop relation %s when other backend attached this global temp table",
+						RelationGetRelationName(rel));
+	}
+
 	/*
 	 * Schedule unlinking of the relation's physical files at commit.
 	 */
@@ -3165,7 +3187,7 @@ RemoveStatistics(Oid relid, AttrNumber attnum)
  * the specified relation.  Caller must hold exclusive lock on rel.
  */
 static void
-RelationTruncateIndexes(Relation heapRelation)
+RelationTruncateIndexes(Relation heapRelation, LOCKMODE lockmode)
 {
 	ListCell   *indlist;
 
@@ -3177,7 +3199,7 @@ RelationTruncateIndexes(Relation heapRelation)
 		IndexInfo  *indexInfo;
 
 		/* Open the index relation; use exclusive lock, just to be sure */
-		currentIndex = index_open(indexId, AccessExclusiveLock);
+		currentIndex = index_open(indexId, lockmode);
 
 		/*
 		 * Fetch info needed for index_build.  Since we know there are no
@@ -3223,8 +3245,13 @@ heap_truncate(List *relids)
 	{
 		Oid			rid = lfirst_oid(cell);
 		Relation	rel;
+		LOCKMODE	lockmode = AccessExclusiveLock;
 
-		rel = table_open(rid, AccessExclusiveLock);
+		/* truncate global temp table only need RowExclusiveLock */
+		if (get_rel_persistence(rid) == RELPERSISTENCE_GLOBAL_TEMP)
+			lockmode = RowExclusiveLock;
+
+		rel = table_open(rid, lockmode);
 		relations = lappend(relations, rel);
 	}
 
@@ -3257,6 +3284,7 @@ void
 heap_truncate_one_rel(Relation rel)
 {
 	Oid			toastrelid;
+	LOCKMODE	lockmode = AccessExclusiveLock;
 
 	/*
 	 * Truncate the relation.  Partitioned tables have no storage, so there is
@@ -3265,23 +3293,37 @@ heap_truncate_one_rel(Relation rel)
 	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
 		return;
 
+	if (RELATION_IS_GLOBAL_TEMP(rel))
+	{
+		if (!gtt_storage_attached(rel->rd_node.relNode))
+			return;
+
+		/*
+		 * Truncate global temp table only need RowExclusiveLock
+		 */
+		lockmode = RowExclusiveLock;
+	}
+
 	/* Truncate the underlying relation */
 	table_relation_nontransactional_truncate(rel);
 
 	/* If the relation has indexes, truncate the indexes too */
-	RelationTruncateIndexes(rel);
+	RelationTruncateIndexes(rel, lockmode);
 
 	/* If there is a toast table, truncate that too */
 	toastrelid = rel->rd_rel->reltoastrelid;
 	if (OidIsValid(toastrelid))
 	{
-		Relation	toastrel = table_open(toastrelid, AccessExclusiveLock);
+		Relation	toastrel = table_open(toastrelid, lockmode);
 
 		table_relation_nontransactional_truncate(toastrel);
-		RelationTruncateIndexes(toastrel);
+		RelationTruncateIndexes(toastrel, lockmode);
 		/* keep the lock... */
 		table_close(toastrel, NoLock);
 	}
+
+	if (RELATION_IS_GLOBAL_TEMP(rel))
+		up_gtt_relstats(rel, 0, 0, 0, RecentXmin, InvalidMultiXactId);
 }
 
 /*
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 7223679..2a0144e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -52,6 +52,7 @@
 #include "catalog/pg_trigger.h"
 #include "catalog/pg_type.h"
 #include "catalog/storage.h"
+#include "catalog/storage_gtt.h"
 #include "commands/event_trigger.h"
 #include "commands/progress.h"
 #include "commands/tablecmds.h"
@@ -877,6 +878,19 @@ index_create(Relation heapRelation,
 						indexRelationName, RelationGetRelationName(heapRelation))));
 	}
 
+	if (RELATION_IS_GLOBAL_TEMP(heapRelation))
+	{
+		/* No support create index on global temp table use concurrent mode yet */
+		if (concurrent)
+			ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("cannot create indexes on global temporary tables using concurrent mode")));
+
+		/* if global temp table not init storage, then skip build index */
+		if (!gtt_storage_attached(heapRelation->rd_node.relNode))
+			flags |= INDEX_CREATE_SKIP_BUILD;
+	}
+
 	/*
 	 * construct tuple descriptor for index tuples
 	 */
@@ -2061,6 +2075,14 @@ index_drop(Oid indexId, bool concurrent, bool concurrent_lock_mode)
 	 */
 	CheckTableNotInUse(userIndexRelation, "DROP INDEX");
 
+	/* We allow to drop index on global temp table only this session use it */
+	if (RELATION_IS_GLOBAL_TEMP(userHeapRelation))
+	{
+		if (is_other_backend_use_gtt(userHeapRelation->rd_node))
+			elog(ERROR, "can not drop index %s when other backend attached this global temp table.",
+						RelationGetRelationName(userHeapRelation));
+	}
+
 	/*
 	 * Drop Index Concurrently is more or less the reverse process of Create
 	 * Index Concurrently.
@@ -2667,6 +2689,11 @@ index_update_stats(Relation rel,
 	HeapTuple	tuple;
 	Form_pg_class rd_rel;
 	bool		dirty;
+	bool		is_gtt = false;
+
+	/* update index stats into localhash and rel_rd_rel for global temp table */
+	if (RELATION_IS_GLOBAL_TEMP(rel))
+		is_gtt = true;
 
 	/*
 	 * We always update the pg_class row using a non-transactional,
@@ -2752,21 +2779,35 @@ index_update_stats(Relation rel,
 		else					/* don't bother for indexes */
 			relallvisible = 0;
 
-		if (rd_rel->relpages != (int32) relpages)
+		if (is_gtt)
+			rel->rd_rel->relpages = (int32) relpages;
+		else if (rd_rel->relpages != (int32) relpages)
 		{
 			rd_rel->relpages = (int32) relpages;
 			dirty = true;
 		}
-		if (rd_rel->reltuples != (float4) reltuples)
+
+		if (is_gtt)
+			rel->rd_rel->reltuples = (float4) reltuples;
+		else if (rd_rel->reltuples != (float4) reltuples)
 		{
 			rd_rel->reltuples = (float4) reltuples;
 			dirty = true;
 		}
-		if (rd_rel->relallvisible != (int32) relallvisible)
+
+		if (is_gtt)
+			rel->rd_rel->relallvisible = (int32) relallvisible;
+		else if (rd_rel->relallvisible != (int32) relallvisible)
 		{
 			rd_rel->relallvisible = (int32) relallvisible;
 			dirty = true;
 		}
+
+		if (is_gtt)
+		{
+			up_gtt_relstats(rel, relpages, reltuples, relallvisible,
+							InvalidTransactionId, InvalidMultiXactId);
+		}
 	}
 
 	/*
@@ -2880,6 +2921,15 @@ index_build(Relation heapRelation,
 		pgstat_progress_update_multi_param(6, index, val);
 	}
 
+	if (RELATION_IS_GLOBAL_TEMP(indexRelation))
+	{
+		if (!gtt_storage_attached(indexRelation->rd_node.relNode))
+		{
+			gtt_force_enable_index(indexRelation);
+			RelationCreateStorage(indexRelation->rd_node, RELPERSISTENCE_GLOBAL_TEMP, indexRelation);
+		}
+	}
+
 	/*
 	 * Call the access method's build procedure
 	 */
@@ -3475,6 +3525,15 @@ reindex_index(Oid indexId, bool skip_constraint_checks, char persistence,
 				 errmsg("cannot reindex temporary tables of other sessions")));
 
 	/*
+	 * Because global temp table cannot change relfilenode
+	 * no support reindex on global temp table yet.
+	 */
+	if (RELATION_IS_GLOBAL_TEMP(iRel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot reindex global temporary tables")));
+
+	/*
 	 * Also check for active uses of the index in the current transaction; we
 	 * don't want to reindex underneath an open indexscan.
 	 */
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 5ff7824..9b58f2a 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -647,6 +647,13 @@ RangeVarAdjustRelationPersistence(RangeVar *newRelation, Oid nspid)
 							 errmsg("cannot create temporary relation in non-temporary schema")));
 			}
 			break;
+		/* global temp table */
+		case RELPERSISTENCE_GLOBAL_TEMP:
+			if (isAnyTempNamespace(nspid))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("cannot create global temp relations in temporary schemas")));
+			break;
 		case RELPERSISTENCE_PERMANENT:
 			if (isTempOrTempToastNamespace(nspid))
 				newRelation->relpersistence = RELPERSISTENCE_TEMP;
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index fddfbf1..2982bc7 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -26,6 +26,7 @@
 #include "access/xlogutils.h"
 #include "catalog/storage.h"
 #include "catalog/storage_xlog.h"
+#include "catalog/storage_gtt.h"
 #include "miscadmin.h"
 #include "storage/freespace.h"
 #include "storage/smgr.h"
@@ -75,7 +76,7 @@ static PendingRelDelete *pendingDeletes = NULL; /* head of linked list */
  * transaction aborts later on, the storage will be destroyed.
  */
 SMgrRelation
-RelationCreateStorage(RelFileNode rnode, char relpersistence)
+RelationCreateStorage(RelFileNode rnode, char relpersistence, Relation rel)
 {
 	PendingRelDelete *pending;
 	SMgrRelation srel;
@@ -85,6 +86,8 @@ RelationCreateStorage(RelFileNode rnode, char relpersistence)
 	switch (relpersistence)
 	{
 		case RELPERSISTENCE_TEMP:
+		/* global temp table use same storage strategy as local temp table */
+		case RELPERSISTENCE_GLOBAL_TEMP:
 			backend = BackendIdForTempRelations();
 			needs_wal = false;
 			break;
@@ -117,6 +120,10 @@ RelationCreateStorage(RelFileNode rnode, char relpersistence)
 	pending->next = pendingDeletes;
 	pendingDeletes = pending;
 
+	/* remember global temp table storage info to localhash */
+	if (relpersistence == RELPERSISTENCE_GLOBAL_TEMP && rel)
+		remember_gtt_storage_info(rnode, rel);
+
 	return srel;
 }
 
@@ -486,8 +493,15 @@ smgrDoPendingDeletes(bool isCommit)
 		smgrdounlinkall(srels, nrels, false);
 
 		for (i = 0; i < nrels; i++)
+		{
 			smgrclose(srels[i]);
 
+			/* clean global temp table flags when transaction commit or rollback */
+			if (SmgrIsTemp(srels[i]) && 
+				gtt_storage_attached(srels[i]->smgr_rnode.node.relNode))
+				forget_gtt_storage_info(srels[i]->smgr_rnode.node.relNode, isCommit);
+		}
+
 		pfree(srels);
 	}
 }
diff --git a/src/backend/catalog/storage_gtt.c b/src/backend/catalog/storage_gtt.c
new file mode 100644
index 0000000..04f7fcc
--- /dev/null
+++ b/src/backend/catalog/storage_gtt.c
@@ -0,0 +1,1261 @@
+/*-------------------------------------------------------------------------
+ *
+ * storage_gtt.c
+ *	  code to create and destroy physical storage for global temparary table
+ *
+ * IDENTIFICATION
+ *	  src/backend/catalog/storage_gtt.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/amapi.h"
+#include "access/genam.h"
+#include "access/htup_details.h"
+#include "access/multixact.h"
+#include "access/table.h"
+#include "access/relation.h"
+#include "access/visibilitymap.h"
+#include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
+#include "access/xlogutils.h"
+#include "catalog/storage.h"
+#include "catalog/storage_xlog.h"
+#include "catalog/storage_gtt.h"
+#include "catalog/heap.h"
+#include "catalog/namespace.h"
+#include "catalog/index.h"
+#include "catalog/pg_type.h"
+#include "catalog/pg_statistic.h"
+#include "commands/tablecmds.h"
+#include "commands/sequence.h"
+#include "funcapi.h"
+#include "nodes/primnodes.h"
+#include "nodes/pg_list.h"
+#include "nodes/execnodes.h"
+#include "miscadmin.h"
+#include "storage/freespace.h"
+#include "storage/smgr.h"
+#include "storage/ipc.h"
+#include "storage/proc.h"
+#include "storage/procarray.h"
+#include "storage/lwlock.h"
+#include "storage/shmem.h"
+#include "storage/sinvaladt.h"
+#include "utils/memutils.h"
+#include "utils/rel.h"
+#include "utils/hsearch.h"
+#include "utils/catcache.h"
+#include "utils/lsyscache.h"
+#include <utils/relcache.h>
+#include "utils/inval.h"
+#include "utils/guc.h"
+
+
+/* Copy from bitmapset.c, because gtt used the function in bitmapset.c */
+#define WORDNUM(x)	((x) / BITS_PER_BITMAPWORD)
+#define BITNUM(x)	((x) % BITS_PER_BITMAPWORD)
+
+#define BITMAPSET_SIZE(nwords)	\
+	(offsetof(Bitmapset, words) + (nwords) * sizeof(bitmapword))
+
+static bool gtt_cleaner_exit_registered = false;
+static HTAB *gtt_storage_local_hash = NULL;
+static HTAB *active_gtt_shared_hash = NULL;
+static MemoryContext gtt_relstats_context = NULL;
+
+/* relfrozenxid of all gtts in the current session */
+static List *gtt_session_relfrozenxid_list = NIL;
+static TransactionId gtt_session_frozenxid = InvalidTransactionId;
+
+typedef struct gtt_ctl_data
+{
+	LWLock			lock;
+	int			max_entry;
+	int			entry_size;
+}gtt_ctl_data;
+
+static gtt_ctl_data *gtt_shared_ctl = NULL;
+
+typedef struct
+{
+	RelFileNode	rnode;
+	Bitmapset	*map;
+	/* bitmap data */
+} gtt_shared_hash_entry;
+
+typedef struct
+{
+	Oid			relid;
+
+	Oid			spcnode;
+	/* pg_class stat */
+	int32		relpages;
+	float4		reltuples;
+	int32		relallvisible;
+	TransactionId relfrozenxid;
+	TransactionId relminmxid;
+	char		relkind;
+	bool		on_commit_delete;
+
+	/* pg_statistic */
+	int			natts;
+	int			*attnum;
+	HeapTuple	*att_stat_tups;
+} gtt_local_hash_entry;
+
+static Size action_gtt_shared_hash_entry_size(void);
+static void gtt_storage_checkin(RelFileNode rnode);
+static void gtt_storage_checkout(RelFileNode rnode, bool skiplock, bool isCommit);
+static void gtt_storage_removeall(int code, Datum arg);
+static void insert_gtt_relfrozenxid_to_ordered_list(Oid relfrozenxid);
+static void remove_gtt_relfrozenxid_from_ordered_list(Oid relfrozenxid);
+static void set_gtt_session_relfrozenxid(void);
+
+Datum pg_get_gtt_statistics(PG_FUNCTION_ARGS);
+Datum pg_get_gtt_relstats(PG_FUNCTION_ARGS);
+Datum pg_gtt_attached_pid(PG_FUNCTION_ARGS);
+Datum pg_list_gtt_relfrozenxids(PG_FUNCTION_ARGS);
+
+
+static Size
+action_gtt_shared_hash_entry_size(void)
+{
+	int 	wordnum;
+	Size	hash_entry_size = 0;
+
+	if (max_active_gtt <= 0)
+		return 0;
+
+	wordnum = WORDNUM(MaxBackends + 1);
+	hash_entry_size += MAXALIGN(sizeof(gtt_shared_hash_entry));
+	hash_entry_size += MAXALIGN(BITMAPSET_SIZE(wordnum + 1));
+
+	return hash_entry_size;
+}
+
+Size
+active_gtt_shared_hash_size(void)
+{
+	Size	size = 0;
+	Size	hash_entry_size = 0;
+
+	if (max_active_gtt <= 0)
+		return 0;
+
+	size = MAXALIGN(sizeof(gtt_ctl_data));
+	hash_entry_size = action_gtt_shared_hash_entry_size();
+	size += hash_estimate_size(max_active_gtt, hash_entry_size);
+
+	return size;
+}
+
+void
+active_gtt_shared_hash_init(void)
+{
+	HASHCTL info;
+	bool	found;
+
+	if (max_active_gtt <= 0)
+		return;
+
+	gtt_shared_ctl =
+		ShmemInitStruct("gtt_shared_ctl",
+						sizeof(gtt_ctl_data),
+						&found);
+
+	if (!found)
+	{
+		LWLockRegisterTranche(LWTRANCHE_GTT_CTL, "gtt_shared_ctl");
+		LWLockInitialize(&gtt_shared_ctl->lock, LWTRANCHE_GTT_CTL);
+		gtt_shared_ctl->max_entry = max_active_gtt;
+		gtt_shared_ctl->entry_size = action_gtt_shared_hash_entry_size();
+	}
+
+	info.keysize = sizeof(RelFileNode);
+	info.entrysize = gtt_shared_ctl->entry_size;
+	active_gtt_shared_hash =
+		ShmemInitHash("active gtt shared hash",
+						gtt_shared_ctl->max_entry,
+						gtt_shared_ctl->max_entry,
+						&info, HASH_ELEM | HASH_BLOBS | HASH_FIXED_SIZE);
+}
+
+static void
+gtt_storage_checkin(RelFileNode rnode)
+{
+	gtt_shared_hash_entry	*entry;
+	bool			found;
+
+	if (max_active_gtt <= 0)
+		return;
+
+	LWLockAcquire(&gtt_shared_ctl->lock, LW_EXCLUSIVE);
+	entry = (gtt_shared_hash_entry *) hash_search(active_gtt_shared_hash,
+												&rnode, HASH_ENTER_NULL, &found);
+
+	if (entry == NULL)
+	{
+		LWLockRelease(&gtt_shared_ctl->lock);
+		ereport(ERROR,
+				(errcode(ERRCODE_OUT_OF_MEMORY),
+				 errmsg("out of shared memory"),
+				 errhint("You might need to increase max_active_global_temporary_table.")));
+	}
+
+	if (found == false)
+	{
+		int			wordnum;
+
+		entry->map = (Bitmapset *)((char *)entry + MAXALIGN(sizeof(gtt_shared_hash_entry)));
+		wordnum = WORDNUM(MaxBackends + 1);
+		memset(entry->map, 0, BITMAPSET_SIZE(wordnum + 1));
+		entry->map->nwords = wordnum + 1;
+	}
+
+	bms_add_member(entry->map, MyBackendId);
+	LWLockRelease(&gtt_shared_ctl->lock);
+}
+
+static void
+gtt_storage_checkout(RelFileNode rnode, bool skiplock, bool isCommit)
+{
+	gtt_shared_hash_entry	*entry;
+
+	if (max_active_gtt <= 0)
+		return;
+
+	if (!skiplock)
+		LWLockAcquire(&gtt_shared_ctl->lock, LW_EXCLUSIVE);
+
+	entry = hash_search(active_gtt_shared_hash,
+					(void *) &(rnode), HASH_FIND, NULL);
+
+	if (entry == NULL)
+	{
+		if (!skiplock)
+			LWLockRelease(&gtt_shared_ctl->lock);
+
+		if (isCommit)
+		{
+			elog(WARNING, "relfilenode %u/%u/%u not exist in gtt shared hash when forget",
+						rnode.dbNode, rnode.spcNode, rnode.relNode);
+		}
+
+		return;
+	}
+
+	Assert(MyBackendId >= 1 && MyBackendId <= MaxBackends);
+	bms_del_member(entry->map, MyBackendId);
+
+	if (bms_is_empty(entry->map))
+	{
+		if (!hash_search(active_gtt_shared_hash, &rnode, HASH_REMOVE, NULL))
+			elog(PANIC, "gtt shared hash table corrupted");
+	}
+
+	if (!skiplock)
+		LWLockRelease(&gtt_shared_ctl->lock);
+
+	return;
+}
+
+Bitmapset *
+copy_active_gtt_bitmap(RelFileNode node)
+{
+	gtt_shared_hash_entry	*entry;
+	Bitmapset	*map_copy = NULL;
+
+	if (max_active_gtt <= 0)
+		return NULL;
+
+	LWLockAcquire(&gtt_shared_ctl->lock, LW_SHARED);
+	entry = hash_search(active_gtt_shared_hash,
+					(void *) &(node), HASH_FIND, NULL);
+
+	if (entry == NULL)
+	{
+		LWLockRelease(&gtt_shared_ctl->lock);
+		return NULL;
+	}
+
+	Assert(entry->map);
+	if (!bms_is_empty(entry->map))
+		map_copy = bms_copy(entry->map);
+
+	LWLockRelease(&gtt_shared_ctl->lock);
+
+	return map_copy;
+}
+
+bool
+is_other_backend_use_gtt(RelFileNode node)
+{
+	gtt_shared_hash_entry	*entry;
+	bool		in_use = false;
+	int			num_use = 0;
+
+	if (max_active_gtt <= 0)
+		return false;
+
+	LWLockAcquire(&gtt_shared_ctl->lock, LW_SHARED);
+	entry = hash_search(active_gtt_shared_hash,
+					(void *) &(node), HASH_FIND, NULL);
+
+	if (entry == NULL)
+	{
+		LWLockRelease(&gtt_shared_ctl->lock);
+		return false;
+	}
+
+	Assert(entry->map);
+	Assert(MyBackendId >= 1 && MyBackendId <= MaxBackends);
+
+	num_use = bms_num_members(entry->map);
+	if (num_use == 0)
+		in_use = false;
+	else if (num_use == 1)
+	{
+		if(bms_is_member(MyBackendId, entry->map))
+			in_use = false;
+		else
+			in_use = true;
+	}
+	else
+		in_use = true;
+
+	LWLockRelease(&gtt_shared_ctl->lock);
+
+	return in_use;
+}
+
+void
+remember_gtt_storage_info(RelFileNode rnode, Relation rel)
+{
+	gtt_local_hash_entry	*entry;
+	MemoryContext			oldcontext;
+	Oid			relid = rnode.relNode;
+	bool		found;
+	int			natts = 0;
+
+	if (max_active_gtt <= 0)
+		ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("Global temporary table feature is disable"),
+			 errhint("You might need to increase max_active_global_temporary_table to enable this feature.")));
+
+	if (RecoveryInProgress())
+		elog(ERROR, "readonly mode not support access global temporary table");
+
+	if (rel->rd_rel->relkind == RELKIND_INDEX &&
+		rel->rd_index &&
+		(!rel->rd_index->indisvalid ||
+		 !rel->rd_index->indisready ||
+		 !rel->rd_index->indislive))
+		 elog(ERROR, "invalid gtt index %s not allow to create storage", RelationGetRelationName(rel));
+
+	if (gtt_storage_local_hash == NULL)
+	{
+#define GTT_LOCAL_HASH_SIZE		1024
+		/* First time through: initialize the hash table */
+		HASHCTL		ctl;
+
+		MemSet(&ctl, 0, sizeof(ctl));
+		ctl.keysize = sizeof(Oid);
+		ctl.entrysize = sizeof(gtt_local_hash_entry);
+		gtt_storage_local_hash =
+			hash_create("global temporary table info",
+						GTT_LOCAL_HASH_SIZE,
+						&ctl, HASH_ELEM | HASH_BLOBS);
+
+		if (!CacheMemoryContext)
+			CreateCacheMemoryContext();
+
+		gtt_relstats_context =
+			AllocSetContextCreate(CacheMemoryContext,
+							"gtt relstats context",
+							ALLOCSET_DEFAULT_SIZES);
+	}
+
+	/* Look up or create an entry */
+	entry = hash_search(gtt_storage_local_hash,
+					(void *) &relid, HASH_ENTER, &found);
+
+	if (found)
+	{
+		elog(ERROR, "backend %d relid %u already exists in global temporary table local hash",
+					MyBackendId, relid);
+	}
+
+	oldcontext = MemoryContextSwitchTo(gtt_relstats_context);
+
+	entry->spcnode = rnode.spcNode;
+	entry->relpages = 0;
+	entry->reltuples = 0;
+	entry->relallvisible = 0;
+	entry->relfrozenxid = InvalidTransactionId;
+	entry->relminmxid = InvalidMultiXactId;
+	entry->relkind = rel->rd_rel->relkind;
+	entry->on_commit_delete = false;
+	entry->natts = 0;
+	entry->attnum = NULL;
+	entry->att_stat_tups = NULL;
+
+	natts = RelationGetNumberOfAttributes(rel);
+	entry->attnum = palloc0(sizeof(int) * natts);
+	entry->att_stat_tups = palloc0(sizeof(HeapTuple) * natts);
+	entry->natts = natts;
+	/* only heap contain transaction information */
+	if (entry->relkind == RELKIND_RELATION)
+	{
+		if (RELATION_GTT_ON_COMMIT_DELETE(rel))
+		{
+			entry->on_commit_delete = true;
+			register_on_commit_action(rel->rd_node.relNode, ONCOMMIT_DELETE_ROWS);
+		}
+
+		entry->relfrozenxid = RecentXmin;
+		entry->relminmxid = GetOldestMultiXactId();
+		insert_gtt_relfrozenxid_to_ordered_list(entry->relfrozenxid);
+		set_gtt_session_relfrozenxid();
+	}
+
+	if (entry->relkind == RELKIND_RELATION ||
+		entry->relkind == RELKIND_SEQUENCE)
+	{
+		gtt_storage_checkin(rnode);
+	}
+
+	MemoryContextSwitchTo(oldcontext);
+
+	if (!gtt_cleaner_exit_registered)
+	{
+		before_shmem_exit(gtt_storage_removeall, 0);
+		gtt_cleaner_exit_registered = true;
+	}
+
+	return;
+}
+
+void
+forget_gtt_storage_info(Oid relid, bool isCommit)
+{
+	gtt_local_hash_entry	*entry = NULL;
+
+	if (max_active_gtt <= 0)
+		return;
+
+	if (gtt_storage_local_hash == NULL)
+		return;
+
+	entry = hash_search(gtt_storage_local_hash,
+				(void *) &(relid), HASH_FIND, NULL);
+
+	if (entry)
+	{
+		int		i;
+
+		if (entry->relkind == RELKIND_RELATION)
+		{
+			Assert(TransactionIdIsNormal(entry->relfrozenxid) || !isCommit);
+			if (TransactionIdIsValid(entry->relfrozenxid))
+			{
+				remove_gtt_relfrozenxid_from_ordered_list(entry->relfrozenxid);
+				set_gtt_session_relfrozenxid();
+			}
+		}
+
+		if (entry->relkind == RELKIND_RELATION ||
+			entry->relkind == RELKIND_SEQUENCE)
+		{
+			RelFileNode rnode;
+			rnode.spcNode = entry->spcnode;
+			rnode.dbNode = MyDatabaseId;
+			rnode.relNode = entry->relid;
+			gtt_storage_checkout(rnode, false, isCommit);
+		}
+
+		for (i = 0; i < entry->natts; i++)
+		{
+			if (entry->att_stat_tups[i])
+			{
+				heap_freetuple(entry->att_stat_tups[i]);
+				entry->att_stat_tups[i] = NULL;
+			}
+		}
+
+		if (entry->attnum)
+			pfree(entry->attnum);
+
+		if (entry->att_stat_tups)
+			pfree(entry->att_stat_tups);
+	}
+
+	hash_search(gtt_storage_local_hash,
+			(void *) &(relid), HASH_REMOVE, NULL);
+
+	return;
+}
+
+/* is the storage file was created in this backend */
+bool
+gtt_storage_attached(Oid relid)
+{
+	bool found;
+
+	if (max_active_gtt <= 0)
+		return false;
+
+	if (gtt_storage_local_hash == NULL)
+		return false;
+
+	hash_search(gtt_storage_local_hash,
+			(void *) &(relid), HASH_FIND, &found);
+
+	return found;
+}
+
+static void
+gtt_storage_removeall(int code, Datum arg)
+{
+	HASH_SEQ_STATUS				status;
+	gtt_local_hash_entry		*entry;
+	int			nrels = 0,
+				maxrels = 0;
+	SMgrRelation	*srels = NULL;
+	RelFileNode		*rnodes = NULL;
+	char			*relkinds = NULL;
+
+	if (gtt_storage_local_hash == NULL)
+		return;
+
+	hash_seq_init(&status, gtt_storage_local_hash);
+	while ((entry = (gtt_local_hash_entry *) hash_seq_search(&status)) != NULL)
+	{
+		SMgrRelation srel;
+		RelFileNode rnode;
+
+		rnode.spcNode = entry->spcnode;
+		rnode.dbNode = MyDatabaseId;
+		rnode.relNode = entry->relid;
+
+		srel = smgropen(rnode, MyBackendId);
+
+		/* allocate the initial array, or extend it, if needed */
+		if (maxrels == 0)
+		{
+			maxrels = 32;
+			srels = palloc(sizeof(SMgrRelation) * maxrels);
+			rnodes = palloc(sizeof(RelFileNode) * maxrels);
+			relkinds = palloc(sizeof(char) * maxrels);
+		}
+		else if (maxrels <= nrels)
+		{
+			maxrels *= 2;
+			srels = repalloc(srels, sizeof(SMgrRelation) * maxrels);
+			rnodes = repalloc(rnodes, sizeof(RelFileNode) * maxrels);
+			relkinds = repalloc(relkinds, sizeof(char) * maxrels);
+		}
+
+		srels[nrels] = srel;
+		rnodes[nrels] = rnode;
+		relkinds[nrels] = entry->relkind;
+		nrels++;
+	}
+
+	if (nrels > 0)
+	{
+		int i;
+
+		smgrdounlinkall(srels, nrels, false);
+
+		LWLockAcquire(&gtt_shared_ctl->lock, LW_EXCLUSIVE);
+		for (i = 0; i < nrels; i++)
+		{
+			smgrclose(srels[i]);
+			if (relkinds[i] == RELKIND_RELATION ||
+				relkinds[i] == RELKIND_SEQUENCE)
+				gtt_storage_checkout(rnodes[i], true, false);
+		}
+		LWLockRelease(&gtt_shared_ctl->lock);
+
+		pfree(srels);
+		pfree(rnodes);
+		pfree(relkinds);
+	}
+
+	MyProc->session_gtt_frozenxid = InvalidTransactionId;
+
+	return;
+}
+
+/*
+ * Update global temp table relstats(relpage/reltuple/relallvisible) 
+ * to local hashtable
+ */
+void
+up_gtt_relstats(Relation relation,
+					BlockNumber num_pages,
+					double num_tuples,
+					BlockNumber num_all_visible_pages,
+					TransactionId relfrozenxid,
+					TransactionId relminmxid)
+{
+	Oid		relid = RelationGetRelid(relation);
+	gtt_local_hash_entry	*entry;
+	bool					found;
+
+	if (max_active_gtt <= 0)
+		return;
+
+	if (gtt_storage_local_hash == NULL)
+		return;
+
+	entry = hash_search(gtt_storage_local_hash,
+					(void *) &relid, HASH_FIND, &found);
+
+	if (!found)
+		return;
+
+	Assert(entry->spcnode);
+
+	if (num_pages >= 0 &&
+		entry->relpages != (int32)num_pages)
+		entry->relpages = (int32)num_pages;
+
+	if (num_tuples >= 0 &&
+		num_tuples != (float4)entry->reltuples)
+		entry->reltuples = (float4)num_tuples;
+
+	/* only heap contain transaction information and relallvisible */
+	if (entry->relkind == RELKIND_RELATION)
+	{
+		if (entry->relallvisible >= 0 &&
+			entry->relallvisible != (int32)num_all_visible_pages)
+		{
+			entry->relallvisible = (int32)num_all_visible_pages;
+		}
+
+		if (TransactionIdIsNormal(relfrozenxid) &&
+			entry->relfrozenxid != relfrozenxid &&
+			(TransactionIdPrecedes(entry->relfrozenxid, relfrozenxid) ||
+			 TransactionIdPrecedes(ReadNewTransactionId(), entry->relfrozenxid)))
+		{
+			remove_gtt_relfrozenxid_from_ordered_list(entry->relfrozenxid);
+			entry->relfrozenxid = relfrozenxid;
+			insert_gtt_relfrozenxid_to_ordered_list(relfrozenxid);
+			set_gtt_session_relfrozenxid();
+		}
+
+		if (MultiXactIdIsValid(relminmxid) &&
+			entry->relminmxid != relminmxid &&
+			(MultiXactIdPrecedes(entry->relminmxid, relminmxid) ||
+			 MultiXactIdPrecedes(ReadNextMultiXactId(), entry->relminmxid)))
+		{
+			entry->relminmxid = relminmxid;
+		}
+	}
+
+	return;
+}
+
+/*
+ * Search global temp table relstats(relpage/reltuple/relallvisible) 
+ * from local hashtable.
+ */
+bool
+get_gtt_relstats(Oid relid, BlockNumber *relpages, double *reltuples,
+				BlockNumber *relallvisible, TransactionId *relfrozenxid,
+				TransactionId *relminmxid)
+{
+	gtt_local_hash_entry	*entry;
+	bool					found;
+
+	if (max_active_gtt <= 0)
+		return false;
+
+	if (gtt_storage_local_hash == NULL)
+		return false;
+
+	entry = hash_search(gtt_storage_local_hash,
+					(void *) &relid, HASH_FIND, &found);
+
+	if (!found)
+		return false;
+
+	Assert(entry->relid == relid);
+
+	if (relpages)
+		*relpages = entry->relpages;
+
+	if (reltuples)
+		*reltuples = entry->reltuples;
+
+	if (relallvisible)
+		*relallvisible = entry->relallvisible;
+
+	if (relfrozenxid)
+		*relfrozenxid = entry->relfrozenxid;
+
+	if (relminmxid)
+		*relminmxid = entry->relminmxid;
+
+	return true;
+}
+
+/*
+ * Update global temp table statistic info(definition is same as pg_statistic)
+ * to local hashtable where ananyze global temp table
+ */
+void
+up_gtt_att_statistic(Oid reloid, int attnum, bool inh, int natts,
+					TupleDesc tupleDescriptor, Datum *values, bool *isnull)
+{
+	gtt_local_hash_entry	*entry;
+	bool					found;
+	MemoryContext			oldcontext;
+	int						i = 0;
+
+	if (max_active_gtt <= 0)
+		return;
+
+	if (gtt_storage_local_hash == NULL)
+		return;
+
+	entry = hash_search(gtt_storage_local_hash,
+						(void *) &reloid, HASH_FIND, &found);
+
+	if (!found)
+		return;
+
+	/* todo */
+	if (entry->natts < natts)
+	{
+		elog(WARNING, "reloid %u not support update attstat after add colunm", reloid);
+		return;
+	}
+
+	oldcontext = MemoryContextSwitchTo(gtt_relstats_context);
+	Assert(entry->relid == reloid);
+	for (i = 0; i < entry->natts; i++)
+	{
+		if (entry->attnum[i] == 0)
+		{
+			entry->attnum[i] = attnum;
+			break;
+		}
+		else if (entry->attnum[i] == attnum)
+		{
+			Assert(entry->att_stat_tups[i]);
+			heap_freetuple(entry->att_stat_tups[i]);
+			entry->att_stat_tups[i] = NULL;
+			break;
+		}
+	}
+
+	Assert(i < entry->natts);
+	Assert(entry->att_stat_tups[i] == NULL);
+	entry->att_stat_tups[i] = heap_form_tuple(tupleDescriptor, values, isnull);
+	MemoryContextSwitchTo(oldcontext);
+
+	return;
+}
+
+/*
+ * Search global temp table statistic info(definition is same as pg_statistic)
+ * from local hashtable.
+ */
+HeapTuple
+get_gtt_att_statistic(Oid reloid, int attnum, bool inh)
+{
+	gtt_local_hash_entry	*entry;
+	bool					found;
+	int						i = 0;
+
+	if (max_active_gtt <= 0)
+		return NULL;
+
+	if (gtt_storage_local_hash == NULL)
+		return NULL;
+
+	entry = hash_search(gtt_storage_local_hash,
+						(void *) &reloid, HASH_FIND, &found);
+
+	if (!found)
+		return NULL;
+
+	for (i = 0; i < entry->natts; i++)
+	{
+		if (entry->attnum[i] == attnum)
+		{
+			Assert(entry->att_stat_tups[i]);
+			return entry->att_stat_tups[i];
+		}
+	}
+
+	return NULL;
+}
+
+void
+release_gtt_statistic_cache(HeapTuple tup)
+{
+	/* do nothing */
+	return;
+}
+
+static void
+insert_gtt_relfrozenxid_to_ordered_list(Oid relfrozenxid)
+{
+	MemoryContext	oldcontext;
+	ListCell	*cell;
+	int			i;
+
+	Assert(TransactionIdIsNormal(relfrozenxid));
+
+	oldcontext = MemoryContextSwitchTo(gtt_relstats_context);
+	/* Does the datum belong at the front? */
+	if (gtt_session_relfrozenxid_list == NIL ||
+		TransactionIdFollowsOrEquals(relfrozenxid,
+			linitial_oid(gtt_session_relfrozenxid_list)))
+	{
+		gtt_session_relfrozenxid_list =
+			lcons_oid(relfrozenxid, gtt_session_relfrozenxid_list);
+		MemoryContextSwitchTo(oldcontext);
+
+		return;
+	}
+
+	/* No, so find the entry it belongs after */
+	i = 0;
+	foreach (cell, gtt_session_relfrozenxid_list)
+	{
+		if (TransactionIdFollowsOrEquals(relfrozenxid, lfirst_oid(cell)))
+			break;
+
+		i++;
+	}
+	gtt_session_relfrozenxid_list =
+		list_insert_nth_oid(gtt_session_relfrozenxid_list, i, relfrozenxid);
+	MemoryContextSwitchTo(oldcontext);
+
+	return;
+}
+
+static void
+remove_gtt_relfrozenxid_from_ordered_list(Oid relfrozenxid)
+{
+	gtt_session_relfrozenxid_list =
+		list_delete_oid(gtt_session_relfrozenxid_list, relfrozenxid);
+}
+
+static void
+set_gtt_session_relfrozenxid(void)
+{
+	TransactionId gtt_frozenxid = InvalidTransactionId;
+
+	if (gtt_session_relfrozenxid_list)
+		gtt_frozenxid = llast_oid(gtt_session_relfrozenxid_list);
+
+	gtt_session_frozenxid = gtt_frozenxid;
+	if (MyProc->session_gtt_frozenxid != gtt_frozenxid)
+		MyProc->session_gtt_frozenxid = gtt_frozenxid;
+}
+
+Datum
+pg_get_gtt_statistics(PG_FUNCTION_ARGS)
+{
+	HeapTuple	tuple;
+	Relation	rel = NULL;
+	int		attnum = PG_GETARG_INT32(1);
+	Oid		reloid = PG_GETARG_OID(0);
+	char		rel_persistence;
+	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc	  tupdesc;
+	MemoryContext oldcontext;
+	Tuplestorestate *tupstore;
+	Relation		pg_tatistic = NULL;
+	TupleDesc		sd;
+
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	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")));
+
+	oldcontext = MemoryContextSwitchTo(
+				rsinfo->econtext->ecxt_per_query_memory);
+
+	tupstore = tuplestore_begin_heap(true, false, work_mem);
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = tupstore;
+	rsinfo->setDesc = tupdesc;
+	MemoryContextSwitchTo(oldcontext);
+
+	rel = table_open(reloid, AccessShareLock);
+	rel_persistence = get_rel_persistence(reloid);
+	if (rel_persistence != RELPERSISTENCE_GLOBAL_TEMP)
+	{
+		elog(WARNING, "relation OID %u is not a global temporary table", reloid);
+		table_close(rel, NoLock);
+		return (Datum) 0;
+	}
+
+	pg_tatistic = table_open(StatisticRelationId, AccessShareLock);
+	sd = RelationGetDescr(pg_tatistic);
+
+	tuple = get_gtt_att_statistic(reloid, attnum, false);
+	if (tuple)
+	{
+		Datum	values[31];
+		bool	isnull[31];
+		HeapTuple	res = NULL;
+
+		memset(&values, 0, sizeof(values));
+		memset(&isnull, 0, sizeof(isnull));
+		heap_deform_tuple(tuple, sd, values, isnull);
+		res = heap_form_tuple(tupdesc, values, isnull);
+		tuplestore_puttuple(tupstore, res);
+	}
+
+	table_close(rel, NoLock);
+	table_close(pg_tatistic, AccessShareLock);
+	tuplestore_donestoring(tupstore);
+
+	return (Datum) 0;
+}
+
+Datum
+pg_get_gtt_relstats(PG_FUNCTION_ARGS)
+{
+	ReturnSetInfo	*rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc		tupdesc;
+	Tuplestorestate	*tupstore;
+	MemoryContext	oldcontext;
+	HeapTuple	tuple;
+	Oid		reloid = PG_GETARG_OID(0);
+	char	rel_persistence;
+	BlockNumber	relpages = 0;
+	double		reltuples = 0;
+	BlockNumber	relallvisible = 0;
+	uint32		relfrozenxid = 0;
+	uint32		relminmxid = 0;
+	Relation	rel = NULL;
+
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	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")));
+
+	oldcontext = MemoryContextSwitchTo(
+			rsinfo->econtext->ecxt_per_query_memory);
+	tupstore = tuplestore_begin_heap(true, false, work_mem);
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = tupstore;
+	rsinfo->setDesc = tupdesc;
+	MemoryContextSwitchTo(oldcontext);
+
+	rel = table_open(reloid, AccessShareLock);
+	rel_persistence = get_rel_persistence(reloid);
+	if (rel_persistence != RELPERSISTENCE_GLOBAL_TEMP)
+	{
+		elog(WARNING, "relation OID %u is not a global temporary table", reloid);
+		table_close(rel, NoLock);
+		return (Datum) 0;
+	}
+
+	if (get_gtt_relstats(reloid,
+						&relpages, &reltuples, &relallvisible,
+						&relfrozenxid, &relminmxid))
+	{
+		Datum	values[5];
+		bool	isnull[5];
+
+		memset(isnull, 0, sizeof(isnull));
+		memset(values, 0, sizeof(values));
+		values[0] = Int32GetDatum(relpages);
+		values[1] = Float4GetDatum((float4)reltuples);
+		values[2] = Int32GetDatum(relallvisible);
+		values[3] = UInt32GetDatum(relfrozenxid);
+		values[4] = UInt32GetDatum(relminmxid);
+		tuple = heap_form_tuple(tupdesc, values, isnull);
+		tuplestore_puttuple(tupstore, tuple);
+	}
+
+	tuplestore_donestoring(tupstore);
+	table_close(rel, NoLock);
+
+	return (Datum) 0;
+}
+
+Datum
+pg_gtt_attached_pid(PG_FUNCTION_ARGS)
+{
+	ReturnSetInfo	*rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc	tupdesc;
+	Tuplestorestate *tupstore;
+	MemoryContext	oldcontext;
+	HeapTuple	tuple;
+	Oid		reloid = PG_GETARG_OID(0);
+	char	rel_persistence;
+	Relation	rel = NULL;
+	PGPROC		*proc = NULL;
+	Bitmapset	*map = NULL;
+	pid_t		pid = 0;
+	int			backendid = 0;
+
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	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")));
+
+	oldcontext = MemoryContextSwitchTo(
+			rsinfo->econtext->ecxt_per_query_memory);
+	tupstore = tuplestore_begin_heap(true, false, work_mem);
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = tupstore;
+	rsinfo->setDesc = tupdesc;
+	MemoryContextSwitchTo(oldcontext);
+
+	rel = table_open(reloid, AccessShareLock);
+	rel_persistence = get_rel_persistence(reloid);
+	if (rel_persistence != RELPERSISTENCE_GLOBAL_TEMP)
+	{
+		elog(WARNING, "relation OID %u is not a global temporary table", reloid);
+		table_close(rel, NoLock);
+		return (Datum) 0;
+	}
+
+	map = copy_active_gtt_bitmap(rel->rd_node);
+	if (map)
+	{
+		backendid = bms_first_member(map);
+
+		do
+		{
+			proc = BackendIdGetProc(backendid);
+			pid = proc->pid;
+			if (pid > 0)
+			{
+				Datum	values[2];
+				bool	isnull[2];
+
+				memset(isnull, false, sizeof(isnull));
+				memset(values, 0, sizeof(values));
+				values[0] = UInt32GetDatum(reloid);
+				values[1] = Int32GetDatum(pid);
+				tuple = heap_form_tuple(tupdesc, values, isnull);
+				tuplestore_puttuple(tupstore, tuple);
+			}
+			backendid = bms_next_member(map, backendid);
+		} while (backendid > 0);
+
+		pfree(map);
+	}
+
+	tuplestore_donestoring(tupstore);
+	table_close(rel, NoLock);
+
+	return (Datum) 0;
+}
+
+Datum
+pg_list_gtt_relfrozenxids(PG_FUNCTION_ARGS)
+{
+	ReturnSetInfo	*rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+	TupleDesc	tupdesc;
+	Tuplestorestate *tupstore;
+	MemoryContext	oldcontext;
+	HeapTuple	tuple;
+	int			num_xid = MaxBackends + 1;
+	int			*pids = NULL;
+	uint32		*xids = NULL;
+	int			i = 0;
+	int			j = 0;
+	uint32		oldest = 0;
+
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	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")));
+
+	oldcontext = MemoryContextSwitchTo(
+			rsinfo->econtext->ecxt_per_query_memory);
+	tupstore = tuplestore_begin_heap(true, false, work_mem);
+	rsinfo->returnMode = SFRM_Materialize;
+	rsinfo->setResult = tupstore;
+	rsinfo->setDesc = tupdesc;
+	MemoryContextSwitchTo(oldcontext);
+
+	if (max_active_gtt <= 0)
+		return (Datum) 0;
+
+	if (RecoveryInProgress())
+		return (Datum) 0;
+
+	pids = palloc0(sizeof(int) * num_xid);
+	xids = palloc0(sizeof(int) * num_xid);
+	oldest = list_all_session_gtt_frozenxids(num_xid, pids, xids, &i);
+	if (i > 0)
+	{
+		if (i > 0)
+		{
+			pids[i] = 0;
+			xids[i] = oldest;
+			i++;
+		}
+
+		for(j = 0; j < i; j++)
+		{
+			Datum	values[2];
+			bool	isnull[2];
+
+			memset(isnull, false, sizeof(isnull));
+			memset(values, 0, sizeof(values));
+			values[0] = Int32GetDatum(pids[j]);
+			values[1] = UInt32GetDatum(xids[j]);
+			tuple = heap_form_tuple(tupdesc, values, isnull);
+			tuplestore_puttuple(tupstore, tuple);
+		}
+	}
+	tuplestore_donestoring(tupstore);
+	pfree(pids);
+	pfree(xids);
+
+	return (Datum) 0;
+}
+
+void
+gtt_force_enable_index(Relation index)
+{
+	Oid indexOid = RelationGetRelid(index);
+
+	if (!RELATION_IS_GLOBAL_TEMP(index))
+		return;
+
+	Assert(index->rd_rel->relkind == RELKIND_INDEX);
+	Assert(OidIsValid(indexOid));
+
+	index->rd_index->indisvalid = true;
+	index->rd_index->indislive = true;
+	index->rd_index->indisready = true;
+}
+
+void
+gtt_fix_index_state(Relation index)
+{
+	Oid indexOid = RelationGetRelid(index);
+	Oid relOid = index->rd_index->indrelid;
+
+	if (!RELATION_IS_GLOBAL_TEMP(index))
+		return;
+
+	if (!index->rd_index->indisvalid)
+		return;
+
+	if (gtt_storage_attached(relOid) &&
+		!gtt_storage_attached(indexOid))
+	{
+		index->rd_index->indisvalid = false;
+		index->rd_index->indislive = false;
+		index->rd_index->indisready = false;
+	}
+
+	return;
+}
+
+void
+init_gtt_storage(CmdType operation, ResultRelInfo *resultRelInfo)
+{
+	Relation	relation = resultRelInfo->ri_RelationDesc;
+	int			i;
+	Oid			toastrelid;
+
+	if (operation != CMD_INSERT)
+		return;
+
+	if (!RELKIND_HAS_STORAGE(relation->rd_rel->relkind))
+		return;
+
+	if (!RELATION_IS_GLOBAL_TEMP(relation))
+		return;
+
+	if (max_active_gtt <= 0)
+		return;
+
+	if (gtt_storage_attached(relation->rd_node.relNode))
+		return;
+
+	RelationCreateStorage(relation->rd_node, RELPERSISTENCE_GLOBAL_TEMP, relation);
+
+	for (i = 0; i < resultRelInfo->ri_NumIndices; i++)
+	{
+		Relation	index = resultRelInfo->ri_IndexRelationDescs[i];
+		IndexInfo	*info = resultRelInfo->ri_IndexRelationInfo[i];
+
+		Assert(index->rd_index->indisvalid);
+		Assert(index->rd_index->indislive);
+		Assert(index->rd_index->indisready);
+
+		index_build(relation, index, info, true, false);
+	}
+
+	toastrelid = relation->rd_rel->reltoastrelid;
+	if (OidIsValid(toastrelid))
+	{
+		Relation	toastrel;
+		ListCell	*indlist;
+
+		toastrel = table_open(toastrelid, RowExclusiveLock);
+		RelationCreateStorage(toastrel->rd_node, RELPERSISTENCE_GLOBAL_TEMP, toastrel);
+
+		foreach(indlist, RelationGetIndexList(toastrel))
+		{
+			Oid 		indexId = lfirst_oid(indlist);
+			Relation	currentIndex;
+			IndexInfo 	*indexInfo;
+
+			currentIndex = index_open(indexId, RowExclusiveLock);
+
+			indexInfo = BuildDummyIndexInfo(currentIndex);
+			index_build(toastrel, currentIndex, indexInfo, true, false);
+			index_close(currentIndex, NoLock);
+		}
+
+		table_close(toastrel, NoLock);
+	}
+
+	return;
+}
+
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index b8a3f46..491db16 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -186,6 +186,91 @@ CREATE OR REPLACE VIEW pg_sequences AS
     WHERE NOT pg_is_other_temp_schema(N.oid)
           AND relkind = 'S';
 
+-- For global temporary table
+CREATE VIEW pg_gtt_relstats WITH (security_barrier) AS
+ SELECT n.nspname AS schemaname,
+    c.relname AS tablename,
+    s.*
+ FROM
+     pg_class c
+     LEFT JOIN pg_namespace n ON n.oid = c.relnamespace,
+     pg_get_gtt_relstats(c.oid) as s
+ WHERE c.relpersistence='g' AND c.relkind in('r','p') AND (c.relrowsecurity = false OR NOT row_security_active(c.oid));
+
+CREATE VIEW pg_gtt_attached_pids WITH (security_barrier) AS
+ SELECT n.nspname AS schemaname,
+    c.relname AS tablename,
+    s.*
+ FROM
+     pg_class c
+     LEFT JOIN pg_namespace n ON n.oid = c.relnamespace,
+     pg_gtt_attached_pid(c.oid) as s
+ WHERE c.relpersistence='g' AND c.relkind in('r','p') AND (c.relrowsecurity = false OR NOT row_security_active(c.oid));
+
+CREATE VIEW pg_gtt_stats WITH (security_barrier) AS
+SELECT n.nspname AS schemaname,
+    c.relname AS tablename,
+    a.attname,
+    s.stainherit AS inherited,
+    s.stanullfrac AS null_frac,
+    s.stawidth AS avg_width,
+    s.stadistinct AS n_distinct,
+        CASE
+            WHEN s.stakind1 = 1 THEN s.stavalues1
+            WHEN s.stakind2 = 1 THEN s.stavalues2
+            WHEN s.stakind3 = 1 THEN s.stavalues3
+            WHEN s.stakind4 = 1 THEN s.stavalues4
+            WHEN s.stakind5 = 1 THEN s.stavalues5
+        END AS most_common_vals,
+        CASE
+            WHEN s.stakind1 = 1 THEN s.stanumbers1
+            WHEN s.stakind2 = 1 THEN s.stanumbers2
+            WHEN s.stakind3 = 1 THEN s.stanumbers3
+            WHEN s.stakind4 = 1 THEN s.stanumbers4
+            WHEN s.stakind5 = 1 THEN s.stanumbers5
+        END AS most_common_freqs,
+        CASE
+            WHEN s.stakind1 = 2 THEN s.stavalues1
+            WHEN s.stakind2 = 2 THEN s.stavalues2
+            WHEN s.stakind3 = 2 THEN s.stavalues3
+            WHEN s.stakind4 = 2 THEN s.stavalues4
+            WHEN s.stakind5 = 2 THEN s.stavalues5
+        END AS histogram_bounds,
+        CASE
+            WHEN s.stakind1 = 3 THEN s.stanumbers1[1]
+            WHEN s.stakind2 = 3 THEN s.stanumbers2[1]
+            WHEN s.stakind3 = 3 THEN s.stanumbers3[1]
+            WHEN s.stakind4 = 3 THEN s.stanumbers4[1]
+            WHEN s.stakind5 = 3 THEN s.stanumbers5[1]
+        END AS correlation,
+        CASE
+            WHEN s.stakind1 = 4 THEN s.stavalues1
+            WHEN s.stakind2 = 4 THEN s.stavalues2
+            WHEN s.stakind3 = 4 THEN s.stavalues3
+            WHEN s.stakind4 = 4 THEN s.stavalues4
+            WHEN s.stakind5 = 4 THEN s.stavalues5
+        END AS most_common_elems,
+        CASE
+            WHEN s.stakind1 = 4 THEN s.stanumbers1
+            WHEN s.stakind2 = 4 THEN s.stanumbers2
+            WHEN s.stakind3 = 4 THEN s.stanumbers3
+            WHEN s.stakind4 = 4 THEN s.stanumbers4
+            WHEN s.stakind5 = 4 THEN s.stanumbers5
+        END AS most_common_elem_freqs,
+        CASE
+            WHEN s.stakind1 = 5 THEN s.stanumbers1
+            WHEN s.stakind2 = 5 THEN s.stanumbers2
+            WHEN s.stakind3 = 5 THEN s.stanumbers3
+            WHEN s.stakind4 = 5 THEN s.stanumbers4
+            WHEN s.stakind5 = 5 THEN s.stanumbers5
+        END AS elem_count_histogram
+   FROM 
+     pg_class c
+     JOIN pg_attribute a ON c.oid = a.attrelid
+     LEFT JOIN pg_namespace n ON n.oid = c.relnamespace,
+     pg_get_gtt_statistics(c.oid, a.attnum, ''::text) as s
+  WHERE c.relpersistence='g' AND c.relkind in('r','p') and NOT a.attisdropped AND has_column_privilege(c.oid, a.attnum, 'select'::text) AND (c.relrowsecurity = false OR NOT row_security_active(c.oid));
+
 CREATE VIEW pg_stats WITH (security_barrier) AS
     SELECT
         nspname AS schemaname,
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 924ef37..7efc5a9 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -34,6 +34,7 @@
 #include "catalog/pg_inherits.h"
 #include "catalog/pg_namespace.h"
 #include "catalog/pg_statistic_ext.h"
+#include "catalog/storage_gtt.h"
 #include "commands/dbcommands.h"
 #include "commands/progress.h"
 #include "commands/tablecmds.h"
@@ -103,7 +104,7 @@ static int	acquire_inherited_sample_rows(Relation onerel, int elevel,
 										  HeapTuple *rows, int targrows,
 										  double *totalrows, double *totaldeadrows);
 static void update_attstats(Oid relid, bool inh,
-							int natts, VacAttrStats **vacattrstats);
+							int natts, VacAttrStats **vacattrstats, char relpersistence);
 static Datum std_fetch_func(VacAttrStatsP stats, int rownum, bool *isNull);
 static Datum ind_fetch_func(VacAttrStatsP stats, int rownum, bool *isNull);
 
@@ -184,6 +185,13 @@ analyze_rel(Oid relid, RangeVar *relation,
 		return;
 	}
 
+	if (RELATION_IS_GLOBAL_TEMP(onerel) &&
+		!gtt_storage_attached(onerel->rd_node.relNode))
+	{
+		relation_close(onerel, ShareUpdateExclusiveLock);
+		return;
+	}
+
 	/*
 	 * We can ANALYZE any table except pg_statistic. See update_attstats
 	 */
@@ -586,14 +594,15 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
 		 * pg_statistic for columns we didn't process, we leave them alone.)
 		 */
 		update_attstats(RelationGetRelid(onerel), inh,
-						attr_cnt, vacattrstats);
+						attr_cnt, vacattrstats, RelationGetRelPersistence(onerel));
 
 		for (ind = 0; ind < nindexes; ind++)
 		{
 			AnlIndexData *thisdata = &indexdata[ind];
 
 			update_attstats(RelationGetRelid(Irel[ind]), false,
-							thisdata->attr_cnt, thisdata->vacattrstats);
+							thisdata->attr_cnt, thisdata->vacattrstats,
+							RelationGetRelPersistence(Irel[ind]));
 		}
 
 		/*
@@ -1456,7 +1465,7 @@ acquire_inherited_sample_rows(Relation onerel, int elevel,
  *		by taking a self-exclusive lock on the relation in analyze_rel().
  */
 static void
-update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
+update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats, char relpersistence)
 {
 	Relation	sd;
 	int			attno;
@@ -1558,31 +1567,45 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
 			}
 		}
 
-		/* Is there already a pg_statistic tuple for this attribute? */
-		oldtup = SearchSysCache3(STATRELATTINH,
-								 ObjectIdGetDatum(relid),
-								 Int16GetDatum(stats->attr->attnum),
-								 BoolGetDatum(inh));
-
-		if (HeapTupleIsValid(oldtup))
+		/* Update column statistic to localhash, not catalog */
+		if (relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 		{
-			/* Yes, replace it */
-			stup = heap_modify_tuple(oldtup,
-									 RelationGetDescr(sd),
-									 values,
-									 nulls,
-									 replaces);
-			ReleaseSysCache(oldtup);
-			CatalogTupleUpdate(sd, &stup->t_self, stup);
+			up_gtt_att_statistic(relid,
+								stats->attr->attnum,
+								inh,
+								natts,
+								RelationGetDescr(sd),
+								values,
+								nulls);
 		}
 		else
 		{
-			/* No, insert new tuple */
-			stup = heap_form_tuple(RelationGetDescr(sd), values, nulls);
-			CatalogTupleInsert(sd, stup);
-		}
+			/* Is there already a pg_statistic tuple for this attribute? */
+			oldtup = SearchSysCache3(STATRELATTINH,
+									 ObjectIdGetDatum(relid),
+									 Int16GetDatum(stats->attr->attnum),
+									 BoolGetDatum(inh));
 
-		heap_freetuple(stup);
+			if (HeapTupleIsValid(oldtup))
+			{
+				/* Yes, replace it */
+				stup = heap_modify_tuple(oldtup,
+										 RelationGetDescr(sd),
+										 values,
+										 nulls,
+										 replaces);
+				ReleaseSysCache(oldtup);
+				CatalogTupleUpdate(sd, &stup->t_self, stup);
+			}
+			else
+			{
+				/* No, insert new tuple */
+				stup = heap_form_tuple(RelationGetDescr(sd), values, nulls);
+				CatalogTupleInsert(sd, stup);
+			}
+
+			heap_freetuple(stup);
+		}
 	}
 
 	table_close(sd, RowExclusiveLock);
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 11ce1bb..552fd87 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -391,6 +391,12 @@ cluster_rel(Oid tableOid, Oid indexOid, int options)
 					 errmsg("cannot vacuum temporary tables of other sessions")));
 	}
 
+	/* not support cluster global temp table yet */
+	if (RELATION_IS_GLOBAL_TEMP(OldHeap))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("not support cluster global temporary tables yet")));
+
 	/*
 	 * Also check for active uses of the relation in the current transaction,
 	 * including open scans and pending AFTER trigger events.
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index e79ede4..078694d 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -27,6 +27,7 @@
 #include "catalog/dependency.h"
 #include "catalog/pg_authid.h"
 #include "catalog/pg_type.h"
+#include "catalog/storage_gtt.h"
 #include "commands/copy.h"
 #include "commands/defrem.h"
 #include "commands/trigger.h"
@@ -1062,7 +1063,7 @@ DoCopy(ParseState *pstate, const CopyStmt *stmt,
 		Assert(rel);
 
 		/* check read-only transaction and parallel mode */
-		if (XactReadOnly && !rel->rd_islocaltemp)
+		if (XactReadOnly && !RELATION_IS_TEMP(rel))
 			PreventCommandIfReadOnly("COPY FROM");
 
 		cstate = BeginCopyFrom(pstate, rel, stmt->filename, stmt->is_program,
@@ -2840,6 +2841,8 @@ CopyFrom(CopyState cstate)
 
 	ExecOpenIndices(resultRelInfo, false);
 
+	init_gtt_storage(CMD_INSERT, resultRelInfo);
+
 	estate->es_result_relations = resultRelInfo;
 	estate->es_num_result_relations = 1;
 	estate->es_result_relation_info = resultRelInfo;
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 3f3a89f..928c01e 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -2586,6 +2586,16 @@ ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
 			!isTempNamespace(classtuple->relnamespace))
 			continue;
 
+		/* not support reindex on global temp table, so skip it */
+		if (classtuple->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+		{
+			ereport(WARNING,
+				(errmsg("global temp table \"%s.%s\" skip reindexed",
+					get_namespace_name(get_rel_namespace(relid)),
+					get_rel_name(relid))));
+			continue;
+		}
+
 		/* Check user/system classification, and optionally skip */
 		if (objectKind == REINDEX_OBJECT_SYSTEM &&
 			!IsSystemClass(relid, classtuple))
diff --git a/src/backend/commands/lockcmds.c b/src/backend/commands/lockcmds.c
index d8cafc4..deecde8 100644
--- a/src/backend/commands/lockcmds.c
+++ b/src/backend/commands/lockcmds.c
@@ -96,7 +96,8 @@ RangeVarCallbackForLockTable(const RangeVar *rv, Oid relid, Oid oldrelid,
 	 * transaction.
 	 */
 	relpersistence = get_rel_persistence(relid);
-	if (relpersistence == RELPERSISTENCE_TEMP)
+	if (relpersistence == RELPERSISTENCE_TEMP ||
+		relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 		MyXactFlags |= XACT_FLAGS_ACCESSEDTEMPNAMESPACE;
 
 	/* Check permissions. */
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 6aab73b..fada1ac 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -30,6 +30,8 @@
 #include "catalog/objectaccess.h"
 #include "catalog/pg_sequence.h"
 #include "catalog/pg_type.h"
+#include "catalog/storage.h"
+#include "catalog/storage_gtt.h"
 #include "commands/defrem.h"
 #include "commands/sequence.h"
 #include "commands/tablecmds.h"
@@ -94,7 +96,7 @@ static HTAB *seqhashtab = NULL; /* hash table for SeqTable items */
  */
 static SeqTableData *last_used_seq = NULL;
 
-static void fill_seq_with_data(Relation rel, HeapTuple tuple);
+static void fill_seq_with_data(Relation rel, HeapTuple tuple, Buffer buf);
 static Relation lock_and_open_sequence(SeqTable seq);
 static void create_seq_hashtable(void);
 static void init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel);
@@ -108,6 +110,7 @@ static void init_params(ParseState *pstate, List *options, bool for_identity,
 						List **owned_by);
 static void do_setval(Oid relid, int64 next, bool iscalled);
 static void process_owned_by(Relation seqrel, List *owned_by, bool for_identity);
+int64 get_seqence_start_value(Oid seqid);
 
 
 /*
@@ -222,7 +225,7 @@ DefineSequence(ParseState *pstate, CreateSeqStmt *seq)
 
 	/* now initialize the sequence's data */
 	tuple = heap_form_tuple(tupDesc, value, null);
-	fill_seq_with_data(rel, tuple);
+	fill_seq_with_data(rel, tuple, InvalidBuffer);
 
 	/* process OWNED BY if given */
 	if (owned_by)
@@ -327,7 +330,7 @@ ResetSequence(Oid seq_relid)
 	/*
 	 * Insert the modified tuple into the new storage file.
 	 */
-	fill_seq_with_data(seq_rel, tuple);
+	fill_seq_with_data(seq_rel, tuple, InvalidBuffer);
 
 	/* Clear local cache so that we don't think we have cached numbers */
 	/* Note that we do not change the currval() state */
@@ -340,17 +343,21 @@ ResetSequence(Oid seq_relid)
  * Initialize a sequence's relation with the specified tuple as content
  */
 static void
-fill_seq_with_data(Relation rel, HeapTuple tuple)
+fill_seq_with_data(Relation rel, HeapTuple tuple, Buffer buf)
 {
-	Buffer		buf;
 	Page		page;
 	sequence_magic *sm;
 	OffsetNumber offnum;
+	bool lockBuffer = false;
 
 	/* Initialize first page of relation with special magic number */
 
-	buf = ReadBuffer(rel, P_NEW);
-	Assert(BufferGetBlockNumber(buf) == 0);
+	if (buf == InvalidBuffer)
+	{
+		buf = ReadBuffer(rel, P_NEW);
+		Assert(BufferGetBlockNumber(buf) == 0);
+		lockBuffer = true;
+	}
 
 	page = BufferGetPage(buf);
 
@@ -360,7 +367,8 @@ fill_seq_with_data(Relation rel, HeapTuple tuple)
 
 	/* Now insert sequence tuple */
 
-	LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
+	if (lockBuffer)
+		LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 
 	/*
 	 * Since VACUUM does not process sequences, we have to force the tuple to
@@ -410,7 +418,8 @@ fill_seq_with_data(Relation rel, HeapTuple tuple)
 
 	END_CRIT_SECTION();
 
-	UnlockReleaseBuffer(buf);
+	if (lockBuffer)
+		UnlockReleaseBuffer(buf);
 }
 
 /*
@@ -502,7 +511,7 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
 		/*
 		 * Insert the modified tuple into the new storage file.
 		 */
-		fill_seq_with_data(seqrel, newdatatuple);
+		fill_seq_with_data(seqrel, newdatatuple, InvalidBuffer);
 	}
 
 	/* process OWNED BY if given */
@@ -611,7 +620,7 @@ nextval_internal(Oid relid, bool check_permissions)
 						RelationGetRelationName(seqrel))));
 
 	/* read-only transactions may only modify temp sequences */
-	if (!seqrel->rd_islocaltemp)
+	if (!RELATION_IS_TEMP(seqrel))
 		PreventCommandIfReadOnly("nextval()");
 
 	/*
@@ -936,7 +945,7 @@ do_setval(Oid relid, int64 next, bool iscalled)
 	ReleaseSysCache(pgstuple);
 
 	/* read-only transactions may only modify temp sequences */
-	if (!seqrel->rd_islocaltemp)
+	if (!RELATION_IS_TEMP(seqrel))
 		PreventCommandIfReadOnly("setval()");
 
 	/*
@@ -1154,6 +1163,13 @@ init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel)
 	/* Return results */
 	*p_elm = elm;
 	*p_rel = seqrel;
+
+	if (RELATION_IS_GLOBAL_TEMP(seqrel) &&
+		!gtt_storage_attached(seqrel->rd_node.relNode))
+	{
+		RelationCreateStorage(seqrel->rd_node, RELPERSISTENCE_GLOBAL_TEMP, seqrel);
+		gtt_init_seq(seqrel);
+	}
 }
 
 
@@ -1954,3 +1970,46 @@ seq_mask(char *page, BlockNumber blkno)
 
 	mask_unused_space(page);
 }
+
+int64
+get_seqence_start_value(Oid seqid)
+{
+	HeapTuple	seqtuple;
+	Form_pg_sequence	seqform;
+	int64		start;
+
+	seqtuple = SearchSysCache1(SEQRELID, ObjectIdGetDatum(seqid));
+	if (!HeapTupleIsValid(seqtuple))
+		elog(ERROR, "cache lookup failed for sequence %u",
+			 seqid);
+
+	seqform = (Form_pg_sequence) GETSTRUCT(seqtuple);
+	start = seqform->seqstart;
+	ReleaseSysCache(seqtuple);
+
+	return start;
+}
+
+void
+gtt_init_seq(Relation rel)
+{
+	/* Initialize sequence for global temporary tables */
+	Datum		value[SEQ_COL_LASTCOL] = {0};
+	bool		null[SEQ_COL_LASTCOL] = {false};
+	HeapTuple	tuple;
+	int64		startv = get_seqence_start_value(RelationGetRelid(rel));
+
+	/*
+	 * last_value from pg_sequence.seqstart
+	 * log_cnt = 0
+	 * is_called = false
+	 */
+	value[SEQ_COL_LASTVAL-1] = Int64GetDatumFast(startv); /* start sequence with 1 */
+
+	tuple = heap_form_tuple(RelationGetDescr(rel), value, null);
+	fill_seq_with_data(rel, tuple, InvalidBuffer);
+	heap_freetuple(tuple);
+
+	return;
+}
+
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 7a13b97..536083e 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -47,6 +47,7 @@
 #include "catalog/storage.h"
 #include "catalog/storage_xlog.h"
 #include "catalog/toasting.h"
+#include "catalog/storage_gtt.h"
 #include "commands/cluster.h"
 #include "commands/comment.h"
 #include "commands/defrem.h"
@@ -553,6 +554,7 @@ static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx,
 								  Relation partitionTbl);
 static List *GetParentedForeignKeyRefs(Relation partition);
 static void ATDetachCheckNoForeignKeyRefs(Relation partition);
+static OnCommitAction gtt_oncommit_option(List *options);
 
 
 /* ----------------------------------------------------------------
@@ -598,6 +600,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	LOCKMODE	parentLockmode;
 	const char *accessMethod = NULL;
 	Oid			accessMethodId = InvalidOid;
+	OnCommitAction	oncommit_action = ONCOMMIT_NOOP;
 
 	/*
 	 * Truncate relname to appropriate length (probably a waste of time, as
@@ -608,8 +611,10 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	/*
 	 * Check consistency of arguments
 	 */
+	/* global temp table same as local temp table */
 	if (stmt->oncommit != ONCOMMIT_NOOP
-		&& stmt->relation->relpersistence != RELPERSISTENCE_TEMP)
+		&& !(stmt->relation->relpersistence == RELPERSISTENCE_TEMP ||
+			 stmt->relation->relpersistence == RELPERSISTENCE_GLOBAL_TEMP))
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 				 errmsg("ON COMMIT can only be used on temporary tables")));
@@ -639,7 +644,9 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	 * code.  This is needed because calling code might not expect untrusted
 	 * tables to appear in pg_temp at the front of its search path.
 	 */
-	if (stmt->relation->relpersistence == RELPERSISTENCE_TEMP
+	/* global temp table same as local temp table */
+	if ((stmt->relation->relpersistence == RELPERSISTENCE_TEMP ||
+		 stmt->relation->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 		&& InSecurityRestrictedOperation())
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
@@ -740,6 +747,55 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	/*
 	 * Parse and validate reloptions, if any.
 	 */
+	/* global temp table */
+	oncommit_action = gtt_oncommit_option(stmt->options);
+	if (stmt->relation->relpersistence == RELPERSISTENCE_GLOBAL_TEMP &&
+		(relkind == RELKIND_RELATION || relkind == RELKIND_PARTITIONED_TABLE))
+	{
+		/* check parent table*/
+		if (inheritOids)
+		{
+			Oid			parent = linitial_oid(inheritOids);
+			Relation	relation = table_open(parent, NoLock);
+
+			if (!RELATION_IS_GLOBAL_TEMP(relation))
+				elog(ERROR, "The parent table must be global temporary table");
+
+			table_close(relation, NoLock);
+		}
+
+		if (oncommit_action != ONCOMMIT_NOOP)
+		{
+			if (stmt->oncommit != ONCOMMIT_NOOP)
+				elog(ERROR, "can not defeine global temp table with on commit and with clause at same time");
+
+			stmt->oncommit = oncommit_action;
+		}
+		else
+		{
+			DefElem *opt = makeNode(DefElem);
+
+			opt->type = T_DefElem;
+			opt->defnamespace = NULL;
+			opt->defname = "on_commit_delete_rows";
+			opt->defaction = DEFELEM_UNSPEC;
+
+			/* use reloptions to remember on commit clause */
+			if (stmt->oncommit == ONCOMMIT_DELETE_ROWS)
+				opt->arg  = (Node *)makeString("true");
+			else if (stmt->oncommit == ONCOMMIT_PRESERVE_ROWS)
+				opt->arg  = (Node *)makeString("false");
+			else if (stmt->oncommit == ONCOMMIT_NOOP)
+				opt->arg  = (Node *)makeString("false");
+			else
+				elog(ERROR, "global temp table not support on commit drop clause");
+
+			stmt->options = lappend(stmt->options, opt);
+		}
+	}
+	else if (oncommit_action != ONCOMMIT_NOOP)
+		elog(ERROR, "The parameter on_commit_delete_rows is exclusive to the global temp table, which cannot be specified by a regular table");
+
 	reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps,
 									 true, false);
 
@@ -1824,7 +1880,8 @@ ExecuteTruncateGuts(List *explicit_rels, List *relids, List *relids_logged,
 		 * table or the current physical file to be thrown away anyway.
 		 */
 		if (rel->rd_createSubid == mySubid ||
-			rel->rd_newRelfilenodeSubid == mySubid)
+			rel->rd_newRelfilenodeSubid == mySubid ||
+			RELATION_IS_GLOBAL_TEMP(rel))
 		{
 			/* Immediate, non-rollbackable truncation is OK */
 			heap_truncate_one_rel(rel);
@@ -3567,6 +3624,14 @@ AlterTable(AlterTableStmt *stmt, LOCKMODE lockmode,
 	/* Caller is required to provide an adequate lock. */
 	rel = relation_open(context->relid, NoLock);
 
+	/* We allow to alter global temp table only this session use it */
+	if (RELATION_IS_GLOBAL_TEMP(rel))
+	{
+		if (is_other_backend_use_gtt(rel->rd_node))
+			elog(ERROR, "can not alter table %s when other backend attached this global temp table",
+						RelationGetRelationName(rel));
+	}
+
 	CheckTableNotInUse(rel, "ALTER TABLE");
 
 	ATController(stmt, rel, stmt->cmds, stmt->relation->inh, lockmode, context);
@@ -8179,6 +8244,12 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 						 errmsg("constraints on temporary tables must involve temporary tables of this session")));
 			break;
+		case RELPERSISTENCE_GLOBAL_TEMP:
+			if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_GLOBAL_TEMP)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("constraints on global temporary tables may reference only global temporary tables")));
+			break;
 	}
 
 	/*
@@ -12647,6 +12718,12 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
 	if (defList == NIL && operation != AT_ReplaceRelOptions)
 		return;					/* nothing to do */
 
+	if (RELATION_IS_GLOBAL_TEMP(rel))
+	{
+		if (gtt_oncommit_option(defList) != ONCOMMIT_NOOP)
+			elog(ERROR, "The global temp table does not allow modification on commit action.");
+	}
+
 	pgclass = table_open(RelationRelationId, RowExclusiveLock);
 
 	/* Fetch heap tuple */
@@ -12849,6 +12926,9 @@ ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode)
 	 */
 	rel = relation_open(tableOid, lockmode);
 
+	if (RELATION_IS_GLOBAL_TEMP(rel))
+		elog(ERROR, "not support alter table set tablespace on global temp table");
+
 	/*
 	 * No work if no change in tablespace.
 	 */
@@ -13221,7 +13301,7 @@ index_copy_data(Relation rel, RelFileNode newrnode)
 	 * NOTE: any conflict in relfilenode value will be caught in
 	 * RelationCreateStorage().
 	 */
-	RelationCreateStorage(newrnode, rel->rd_rel->relpersistence);
+	RelationCreateStorage(newrnode, rel->rd_rel->relpersistence, rel);
 
 	/* copy main fork */
 	RelationCopyStorage(rel->rd_smgr, dstrel, MAIN_FORKNUM,
@@ -14628,7 +14708,9 @@ ATPrepChangePersistence(Relation rel, bool toLogged)
 	 */
 	switch (rel->rd_rel->relpersistence)
 	{
+		/* global temp table same as local temp table */
 		case RELPERSISTENCE_TEMP:
+		case RELPERSISTENCE_GLOBAL_TEMP:
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 					 errmsg("cannot change logged status of table \"%s\" because it is temporary",
@@ -17220,3 +17302,28 @@ ATDetachCheckNoForeignKeyRefs(Relation partition)
 		table_close(rel, NoLock);
 	}
 }
+
+static OnCommitAction
+gtt_oncommit_option(List *options)
+{
+	ListCell		*listptr;
+	OnCommitAction	action = ONCOMMIT_NOOP;
+
+	foreach(listptr, options)
+	{
+		DefElem    *def = (DefElem *) lfirst(listptr);
+
+		if (strcmp(def->defname, "on_commit_delete_rows") == 0)
+		{
+			if (defGetBoolean(def))
+				action = ONCOMMIT_DELETE_ROWS;
+			else
+				action = ONCOMMIT_PRESERVE_ROWS;
+
+			break;
+		}
+	}
+
+	return action;
+}
+
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index d625d17..f58c44d 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -35,6 +35,7 @@
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
 #include "catalog/pg_namespace.h"
+#include "catalog/storage_gtt.h"
 #include "commands/cluster.h"
 #include "commands/defrem.h"
 #include "commands/vacuum.h"
@@ -1217,6 +1218,17 @@ vac_update_relstats(Relation relation,
 	HeapTuple	ctup;
 	Form_pg_class pgcform;
 	bool		dirty;
+	bool		is_gtt = false;
+
+	 /* global temp table remember relstats to localhash and rel->rd_rel, not catalog */
+	if (RELATION_IS_GLOBAL_TEMP(relation))
+	{
+		is_gtt = true;
+		up_gtt_relstats(relation,
+						num_pages, num_tuples,
+						num_all_visible_pages,
+						frozenxid, minmulti);
+	}
 
 	rd = table_open(RelationRelationId, RowExclusiveLock);
 
@@ -1230,17 +1242,26 @@ vac_update_relstats(Relation relation,
 	/* Apply statistical updates, if any, to copied tuple */
 
 	dirty = false;
-	if (pgcform->relpages != (int32) num_pages)
+
+	if (is_gtt)
+		relation->rd_rel->relpages = (int32) num_pages;
+	else if (pgcform->relpages != (int32) num_pages)
 	{
 		pgcform->relpages = (int32) num_pages;
 		dirty = true;
 	}
-	if (pgcform->reltuples != (float4) num_tuples)
+
+	if (is_gtt)
+		relation->rd_rel->reltuples = (float4) num_tuples;
+	else if (pgcform->reltuples != (float4) num_tuples)
 	{
 		pgcform->reltuples = (float4) num_tuples;
 		dirty = true;
 	}
-	if (pgcform->relallvisible != (int32) num_all_visible_pages)
+
+	if (is_gtt)
+		relation->rd_rel->relallvisible = (int32) num_all_visible_pages;
+	else if (pgcform->relallvisible != (int32) num_all_visible_pages)
 	{
 		pgcform->relallvisible = (int32) num_all_visible_pages;
 		dirty = true;
@@ -1285,7 +1306,8 @@ vac_update_relstats(Relation relation,
 	 * This should match vac_update_datfrozenxid() concerning what we consider
 	 * to be "in the future".
 	 */
-	if (TransactionIdIsNormal(frozenxid) &&
+	if (!is_gtt &&
+		TransactionIdIsNormal(frozenxid) &&
 		pgcform->relfrozenxid != frozenxid &&
 		(TransactionIdPrecedes(pgcform->relfrozenxid, frozenxid) ||
 		 TransactionIdPrecedes(ReadNewTransactionId(),
@@ -1296,7 +1318,8 @@ vac_update_relstats(Relation relation,
 	}
 
 	/* Similarly for relminmxid */
-	if (MultiXactIdIsValid(minmulti) &&
+	if (!is_gtt &&
+		MultiXactIdIsValid(minmulti) &&
 		pgcform->relminmxid != minmulti &&
 		(MultiXactIdPrecedes(pgcform->relminmxid, minmulti) ||
 		 MultiXactIdPrecedes(ReadNextMultiXactId(), pgcform->relminmxid)))
@@ -1394,6 +1417,10 @@ vac_update_datfrozenxid(void)
 			continue;
 		}
 
+		/* global temp table relstats not in pg_class */
+		if (classForm->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+			continue;
+
 		/*
 		 * Some table AMs might not need per-relation xid / multixid horizons.
 		 * It therefore seems reasonable to allow relfrozenxid and relminmxid
@@ -1451,6 +1478,25 @@ vac_update_datfrozenxid(void)
 	Assert(TransactionIdIsNormal(newFrozenXid));
 	Assert(MultiXactIdIsValid(newMinMulti));
 
+	/*
+	 * Global temp table get frozenxid from MyProc
+	 * to avoid the vacuum truncate clog that gtt need.
+	 */
+	if (max_active_gtt > 0)
+	{
+		TransactionId oldest_gtt_frozenxid =
+			list_all_session_gtt_frozenxids(0, NULL, NULL, NULL);
+
+		if (TransactionIdIsNormal(oldest_gtt_frozenxid) &&
+			TransactionIdPrecedes(oldest_gtt_frozenxid, newFrozenXid))
+		{
+			ereport(WARNING,
+				(errmsg("global temp table oldest FrozenXid is far in the past"),
+				 errhint("please truncate them or kill those sessions that use them.")));
+			newFrozenXid = oldest_gtt_frozenxid;
+		}
+	}
+
 	/* Now fetch the pg_database tuple we need to update. */
 	relation = table_open(DatabaseRelationId, RowExclusiveLock);
 
@@ -1778,6 +1824,18 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 		return false;
 	}
 
+	if (RELATION_IS_GLOBAL_TEMP(onerel) &&
+		!gtt_storage_attached(onerel->rd_node.relNode))
+	{
+		ereport(WARNING,
+				(errmsg("skipping vacuum empty global temp table \"%s\"",
+						RelationGetRelationName(onerel))));
+		relation_close(onerel, lmode);
+		PopActiveSnapshot();
+		CommitTransactionCommand();
+		return false;
+	}
+
 	/*
 	 * Silently ignore tables that are temp tables of other backends ---
 	 * trying to vacuum these will lead to great unhappiness, since their
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 28130fb..dcb4a0b 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -787,6 +787,9 @@ ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
 		if (isTempNamespace(get_rel_namespace(rte->relid)))
 			continue;
 
+		if (get_rel_persistence(rte->relid) == RELPERSISTENCE_GLOBAL_TEMP)
+			continue;
+
 		PreventCommandIfReadOnly(CreateCommandName((Node *) plannedstmt));
 	}
 
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index c13b1d3..253054d 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -18,6 +18,7 @@
 #include "catalog/partition.h"
 #include "catalog/pg_inherits.h"
 #include "catalog/pg_type.h"
+#include "catalog/storage_gtt.h"
 #include "executor/execPartition.h"
 #include "executor/executor.h"
 #include "foreign/fdwapi.h"
@@ -543,6 +544,8 @@ ExecInitPartitionInfo(ModifyTableState *mtstate, EState *estate,
 						(node != NULL &&
 						 node->onConflictAction != ONCONFLICT_NONE));
 
+	init_gtt_storage(mtstate->operation, leaf_part_rri);
+
 	/*
 	 * Build WITH CHECK OPTION constraints for the partition.  Note that we
 	 * didn't build the withCheckOptionList for partitions within the planner,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index d71c0a4..0900907 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -42,6 +42,7 @@
 #include "access/tableam.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"
+#include "catalog/storage_gtt.h"
 #include "commands/trigger.h"
 #include "executor/execPartition.h"
 #include "executor/executor.h"
@@ -2372,6 +2373,8 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
 			ExecOpenIndices(resultRelInfo,
 							node->onConflictAction != ONCONFLICT_NONE);
 
+		init_gtt_storage(operation, resultRelInfo);
+
 		/*
 		 * If this is an UPDATE and a BEFORE UPDATE trigger is present, the
 		 * trigger itself might modify the partition-key values. So arrange
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 905bbe7..170963d 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -591,6 +591,8 @@ static void
 set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
 						  RangeTblEntry *rte)
 {
+	char relpersistence;
+
 	/*
 	 * The flag has previously been initialized to false, so we can just
 	 * return if it becomes clear that we can't safely set it.
@@ -618,7 +620,11 @@ set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
 			 * the rest of the necessary infrastructure right now anyway.  So
 			 * for now, bail out if we see a temporary table.
 			 */
-			if (get_rel_persistence(rte->relid) == RELPERSISTENCE_TEMP)
+			/* global temp table is same as local temp table */
+			relpersistence = get_rel_persistence(rte->relid);
+
+			if (relpersistence == RELPERSISTENCE_TEMP ||
+				relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 				return;
 
 			/*
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index b44efd6..14dbaaf 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -6307,7 +6307,9 @@ plan_create_index_workers(Oid tableOid, Oid indexOid)
 	 * Furthermore, any index predicate or index expressions must be parallel
 	 * safe.
 	 */
+	/* global temp table is same as local temp table */
 	if (heap->rd_rel->relpersistence == RELPERSISTENCE_TEMP ||
+		heap->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP ||
 		!is_parallel_safe(root, (Node *) RelationGetIndexExpressions(index)) ||
 		!is_parallel_safe(root, (Node *) RelationGetIndexPredicate(index)))
 	{
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index d82fc5a..93c6d97 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -28,6 +28,7 @@
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
 #include "catalog/heap.h"
+#include "catalog/storage_gtt.h"
 #include "catalog/pg_am.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_statistic_ext.h"
@@ -221,6 +222,14 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 				continue;
 			}
 
+			/* Ignore empty index for global temp table */
+			if (RELATION_IS_GLOBAL_TEMP(indexRelation) &&
+				!gtt_storage_attached(indexRelation->rd_node.relNode))
+			{
+				index_close(indexRelation, NoLock);
+				continue;
+			}
+
 			/*
 			 * If the index is valid, but cannot yet be used, ignore it; but
 			 * mark the plan we are generating as transient. See
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 6676412..0685c1c 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2585,6 +2585,11 @@ transformCreateTableAsStmt(ParseState *pstate, CreateTableAsStmt *stmt)
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("materialized views must not use temporary tables or views")));
 
+		if (is_query_using_gtt(query))
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("materialized views must not use global temporary tables or views")));
+
 		/*
 		 * A materialized view would either need to save parameters for use in
 		 * maintaining/loading the data or prohibit them entirely.  The latter
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 96e7fdb..30f585c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3290,17 +3290,11 @@ OptTemp:	TEMPORARY					{ $$ = RELPERSISTENCE_TEMP; }
 			| LOCAL TEMP				{ $$ = RELPERSISTENCE_TEMP; }
 			| GLOBAL TEMPORARY
 				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
-					$$ = RELPERSISTENCE_TEMP;
+					$$ = RELPERSISTENCE_GLOBAL_TEMP;
 				}
 			| GLOBAL TEMP
 				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
-					$$ = RELPERSISTENCE_TEMP;
+					$$ = RELPERSISTENCE_GLOBAL_TEMP;
 				}
 			| UNLOGGED					{ $$ = RELPERSISTENCE_UNLOGGED; }
 			| /*EMPTY*/					{ $$ = RELPERSISTENCE_PERMANENT; }
@@ -11594,19 +11588,13 @@ OptTempTableName:
 				}
 			| GLOBAL TEMPORARY opt_table qualified_name
 				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
 					$$ = $4;
-					$$->relpersistence = RELPERSISTENCE_TEMP;
+					$$->relpersistence = RELPERSISTENCE_GLOBAL_TEMP;
 				}
 			| GLOBAL TEMP opt_table qualified_name
 				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
 					$$ = $4;
-					$$->relpersistence = RELPERSISTENCE_TEMP;
+					$$->relpersistence = RELPERSISTENCE_GLOBAL_TEMP;
 				}
 			| UNLOGGED opt_table qualified_name
 				{
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index b875a50..123945b 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -81,6 +81,7 @@ static void expandTupleDesc(TupleDesc tupdesc, Alias *eref,
 							List **colnames, List **colvars);
 static int	specialAttNum(const char *attname);
 static bool isQueryUsingTempRelation_walker(Node *node, void *context);
+static bool is_query_using_gtt_walker(Node *node, void *context);
 
 
 /*
@@ -3579,3 +3580,49 @@ isQueryUsingTempRelation_walker(Node *node, void *context)
 								  isQueryUsingTempRelation_walker,
 								  context);
 }
+
+/* check if the query uses global temp table */
+static bool
+is_query_using_gtt_walker(Node *node, void *context)
+{
+	if (node == NULL)
+		return false;
+
+	if (IsA(node, Query))
+	{
+		Query	   *query = (Query *) node;
+		ListCell   *rtable;
+
+		foreach(rtable, query->rtable)
+		{
+			RangeTblEntry *rte = lfirst(rtable);
+
+			if (rte->rtekind == RTE_RELATION)
+			{
+				Relation	rel = relation_open(rte->relid, AccessShareLock);
+				char		relpersistence = rel->rd_rel->relpersistence;
+
+				relation_close(rel, AccessShareLock);
+				if (relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+					return true;
+			}
+		}
+
+		return query_tree_walker(query,
+								 is_query_using_gtt_walker,
+								 context,
+								 QTW_IGNORE_JOINALIASES);
+	}
+
+	return expression_tree_walker(node,
+								  is_query_using_gtt_walker,
+								  context);
+}
+
+/* check if the query uses global temp table */
+bool
+is_query_using_gtt(Query *query)
+{
+	return is_query_using_gtt_walker((Node *) query, NULL);
+}
+
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index af77f18..67d34f0 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -437,6 +437,9 @@ generateSerialExtraStmts(CreateStmtContext *cxt, ColumnDef *column,
 	seqstmt->sequence = makeRangeVar(snamespace, sname, -1);
 	seqstmt->options = seqoptions;
 
+	if (cxt->relation->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+		seqstmt->sequence->relpersistence = cxt->relation->relpersistence;
+
 	/*
 	 * If a sequence data type was specified, add it to the options.  Prepend
 	 * to the list rather than append; in case a user supplied their own AS
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index e3a43d3..ca460ca 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2087,6 +2087,11 @@ do_autovacuum(void)
 			}
 			continue;
 		}
+		else if (classForm->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+		{
+			/* autovacuum skip vacuum global temp table */
+			continue;
+		}
 
 		/* Fetch reloptions and the pgstat entry for this table */
 		relopts = extract_autovac_opts(tuple, pg_class_desc);
@@ -2153,7 +2158,9 @@ do_autovacuum(void)
 		/*
 		 * We cannot safely process other backends' temp tables, so skip 'em.
 		 */
-		if (classForm->relpersistence == RELPERSISTENCE_TEMP)
+		/* autovacuum skip vacuum global temp table */
+		if (classForm->relpersistence == RELPERSISTENCE_TEMP || 
+			classForm->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 			continue;
 
 		relid = classForm->oid;
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 5880054..98f7b43 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -37,6 +37,7 @@
 #include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/storage.h"
+#include "catalog/storage_gtt.h"
 #include "executor/instrument.h"
 #include "lib/binaryheap.h"
 #include "miscadmin.h"
@@ -52,6 +53,7 @@
 #include "utils/rel.h"
 #include "utils/resowner_private.h"
 #include "utils/timestamp.h"
+#include "utils/guc.h"
 
 
 /* Note: these two macros only work on shared buffers, not local ones! */
@@ -2809,6 +2811,16 @@ FlushBuffer(BufferDesc *buf, SMgrRelation reln)
 BlockNumber
 RelationGetNumberOfBlocksInFork(Relation relation, ForkNumber forkNum)
 {
+	/*
+	 * When this backend not init gtt storage
+	 * return 0
+	 */
+	if (RELATION_IS_GLOBAL_TEMP(relation) &&
+		!gtt_storage_attached(relation->rd_node.relNode))
+	{
+		return 0;
+	}
+
 	switch (relation->rd_rel->relkind)
 	{
 		case RELKIND_SEQUENCE:
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 427b0d5..7adb969 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -21,6 +21,7 @@
 #include "access/nbtree.h"
 #include "access/subtrans.h"
 #include "access/twophase.h"
+#include "catalog/storage_gtt.h"
 #include "commands/async.h"
 #include "miscadmin.h"
 #include "pgstat.h"
@@ -147,6 +148,7 @@ CreateSharedMemoryAndSemaphores(void)
 		size = add_size(size, BTreeShmemSize());
 		size = add_size(size, SyncScanShmemSize());
 		size = add_size(size, AsyncShmemSize());
+		size = add_size(size, active_gtt_shared_hash_size());
 #ifdef EXEC_BACKEND
 		size = add_size(size, ShmemBackendArraySize());
 #endif
@@ -217,6 +219,8 @@ CreateSharedMemoryAndSemaphores(void)
 	SUBTRANSShmemInit();
 	MultiXactShmemInit();
 	InitBufferPool();
+	/* global temporary table */
+	active_gtt_shared_hash_init();
 
 	/*
 	 * Set up lock manager
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 4a5b26c..9754168 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -62,6 +62,7 @@
 #include "utils/builtins.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
+#include "utils/guc.h"
 
 #define UINT32_ACCESS_ONCE(var)		 ((uint32)(*((volatile uint32 *)&(var))))
 
@@ -4087,3 +4088,77 @@ KnownAssignedXidsReset(void)
 
 	LWLockRelease(ProcArrayLock);
 }
+
+/*
+ * search all active backend to get oldest frozenxid
+ * for global temp table.
+ */
+int
+list_all_session_gtt_frozenxids(int max_size, int *pids, uint32 *xids, int *n)
+{
+	ProcArrayStruct *arrayP = procArray;
+	TransactionId result = InvalidTransactionId;
+	int			index;
+	int			flags = 0;
+	int			i = 0;
+
+	if (max_active_gtt <= 0)
+		return 0;
+
+	if (max_size > 0)
+	{
+		Assert(pids);
+		Assert(xids);
+		Assert(n);
+		*n = 0;
+	}
+
+	if (max_active_gtt <= 0)
+		return InvalidTransactionId;
+
+	if (RecoveryInProgress())
+		return InvalidTransactionId;
+
+	flags |= PROC_IS_AUTOVACUUM;
+	flags |= PROC_IN_LOGICAL_DECODING;
+
+	LWLockAcquire(ProcArrayLock, LW_SHARED);
+	if (max_size > 0 && max_size < arrayP->numProcs)
+	{
+		LWLockRelease(ProcArrayLock);
+		elog(ERROR, "list_all_gtt_frozenxids require more array");
+	}
+
+	for (index = 0; index < arrayP->numProcs; index++)
+	{
+		int			pgprocno = arrayP->pgprocnos[index];
+		volatile PGPROC *proc = &allProcs[pgprocno];
+		volatile PGXACT *pgxact = &allPgXact[pgprocno];
+
+		if (pgxact->vacuumFlags & flags)
+			continue;
+
+		if (proc->databaseId == MyDatabaseId &&
+			TransactionIdIsNormal(proc->session_gtt_frozenxid))
+		{
+			if (result == InvalidTransactionId)
+				result = proc->session_gtt_frozenxid;
+			else if (TransactionIdPrecedes(proc->session_gtt_frozenxid, result))
+				result = proc->session_gtt_frozenxid;
+
+			if (max_size > 0)
+			{
+				pids[i] = proc->pid;
+				xids[i] = proc->session_gtt_frozenxid;
+				i++;
+			}
+		}
+	}
+	LWLockRelease(ProcArrayLock);
+
+	if (max_size > 0)
+		*n = i;
+
+	return result;
+}
+
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index eb321f7..3893cef 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -395,6 +395,7 @@ InitProcess(void)
 	MyProc->databaseId = InvalidOid;
 	MyProc->roleId = InvalidOid;
 	MyProc->tempNamespaceId = InvalidOid;
+	MyProc->session_gtt_frozenxid = InvalidTransactionId;	/* init session level gtt frozenxid */
 	MyProc->isBackgroundWorker = IsBackgroundWorker;
 	MyPgXact->delayChkpt = false;
 	MyPgXact->vacuumFlags = 0;
@@ -577,6 +578,7 @@ InitAuxiliaryProcess(void)
 	MyProc->databaseId = InvalidOid;
 	MyProc->roleId = InvalidOid;
 	MyProc->tempNamespaceId = InvalidOid;
+	MyProc->session_gtt_frozenxid = InvalidTransactionId;	/* init session level gtt frozenxid */
 	MyProc->isBackgroundWorker = IsBackgroundWorker;
 	MyPgXact->delayChkpt = false;
 	MyPgXact->vacuumFlags = 0;
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 8406644..0d99321 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -1008,6 +1008,9 @@ pg_relation_filepath(PG_FUNCTION_ARGS)
 				Assert(backend != InvalidBackendId);
 			}
 			break;
+		case RELPERSISTENCE_GLOBAL_TEMP:
+			backend = BackendIdForTempRelations();
+			break;
 		default:
 			elog(ERROR, "invalid relpersistence: %c", relform->relpersistence);
 			backend = InvalidBackendId; /* placate compiler */
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 0be26fe..c169c99 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -112,6 +112,7 @@
 #include "catalog/pg_operator.h"
 #include "catalog/pg_statistic.h"
 #include "catalog/pg_statistic_ext.h"
+#include "catalog/storage_gtt.h"
 #include "executor/nodeAgg.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
@@ -4570,12 +4571,25 @@ examine_variable(PlannerInfo *root, Node *node, int varRelid,
 						}
 						else if (index->indpred == NIL)
 						{
-							vardata->statsTuple =
-								SearchSysCache3(STATRELATTINH,
-												ObjectIdGetDatum(index->indexoid),
-												Int16GetDatum(pos + 1),
-												BoolGetDatum(false));
-							vardata->freefunc = ReleaseSysCache;
+							char rel_persistence = get_rel_persistence(index->indexoid);
+
+							if (rel_persistence == RELPERSISTENCE_GLOBAL_TEMP)
+							{
+								vardata->statsTuple =
+									get_gtt_att_statistic(index->indexoid,
+														Int16GetDatum(pos + 1),
+														false);
+								vardata->freefunc = release_gtt_statistic_cache;
+							}
+							else
+							{
+								vardata->statsTuple =
+									SearchSysCache3(STATRELATTINH,
+													ObjectIdGetDatum(index->indexoid),
+													Int16GetDatum(pos + 1),
+													BoolGetDatum(false));
+								vardata->freefunc = ReleaseSysCache;
+							}
 
 							if (HeapTupleIsValid(vardata->statsTuple))
 							{
@@ -4700,15 +4714,27 @@ examine_simple_variable(PlannerInfo *root, Var *var,
 	}
 	else if (rte->rtekind == RTE_RELATION)
 	{
-		/*
-		 * Plain table or parent of an inheritance appendrel, so look up the
-		 * column in pg_statistic
-		 */
-		vardata->statsTuple = SearchSysCache3(STATRELATTINH,
-											  ObjectIdGetDatum(rte->relid),
-											  Int16GetDatum(var->varattno),
-											  BoolGetDatum(rte->inh));
-		vardata->freefunc = ReleaseSysCache;
+		char rel_persistence = get_rel_persistence(rte->relid);
+
+		if (rel_persistence == RELPERSISTENCE_GLOBAL_TEMP)
+		{
+			vardata->statsTuple = get_gtt_att_statistic(rte->relid,
+														var->varattno,
+														rte->inh);
+			vardata->freefunc = release_gtt_statistic_cache;
+		}
+		else
+		{
+			/*
+			 * Plain table or parent of an inheritance appendrel, so look up the
+			 * column in pg_statistic
+			 */
+			vardata->statsTuple = SearchSysCache3(STATRELATTINH,
+												  ObjectIdGetDatum(rte->relid),
+												  Int16GetDatum(var->varattno),
+												  BoolGetDatum(rte->inh));
+			vardata->freefunc = ReleaseSysCache;
+		}
 
 		if (HeapTupleIsValid(vardata->statsTuple))
 		{
@@ -6090,6 +6116,7 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 	{
 		/* Simple variable --- look to stats for the underlying table */
 		RangeTblEntry *rte = planner_rt_fetch(index->rel->relid, root);
+		char	rel_persistence = get_rel_persistence(rte->relid);
 
 		Assert(rte->rtekind == RTE_RELATION);
 		relid = rte->relid;
@@ -6107,6 +6134,13 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 				!vardata.freefunc)
 				elog(ERROR, "no function provided to release variable stats with");
 		}
+		else if (rel_persistence == RELPERSISTENCE_GLOBAL_TEMP)
+		{
+			vardata.statsTuple = get_gtt_att_statistic(relid,
+													colnum,
+													rte->inh);
+			vardata.freefunc = release_gtt_statistic_cache;
+		}
 		else
 		{
 			vardata.statsTuple = SearchSysCache3(STATRELATTINH,
@@ -6118,6 +6152,8 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 	}
 	else
 	{
+		char	rel_persistence = get_rel_persistence(index->indexoid);
+
 		/* Expression --- maybe there are stats for the index itself */
 		relid = index->indexoid;
 		colnum = 1;
@@ -6133,6 +6169,13 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 				!vardata.freefunc)
 				elog(ERROR, "no function provided to release variable stats with");
 		}
+		else if (rel_persistence == RELPERSISTENCE_GLOBAL_TEMP)
+		{
+			vardata.statsTuple = get_gtt_att_statistic(relid,
+													colnum,
+													false);
+			vardata.freefunc = release_gtt_statistic_cache;
+		}
 		else
 		{
 			vardata.statsTuple = SearchSysCache3(STATRELATTINH,
@@ -7046,6 +7089,8 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 		/* attempt to lookup stats in relation for this index column */
 		if (attnum != 0)
 		{
+			char	rel_persistence = get_rel_persistence(rte->relid);
+
 			/* Simple variable -- look to stats for the underlying table */
 			if (get_relation_stats_hook &&
 				(*get_relation_stats_hook) (root, rte, attnum, &vardata))
@@ -7058,6 +7103,14 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 					elog(ERROR,
 						 "no function provided to release variable stats with");
 			}
+			else if (rel_persistence == RELPERSISTENCE_GLOBAL_TEMP)
+			{
+				vardata.statsTuple =
+					get_gtt_att_statistic(rte->relid,
+										attnum,
+										false);
+				vardata.freefunc = release_gtt_statistic_cache;
+			}
 			else
 			{
 				vardata.statsTuple =
@@ -7070,6 +7123,8 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 		}
 		else
 		{
+			char	rel_persistence = get_rel_persistence(index->indexoid);
+
 			/*
 			 * Looks like we've found an expression column in the index. Let's
 			 * see if there's any stats for it.
@@ -7089,6 +7144,14 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 					!vardata.freefunc)
 					elog(ERROR, "no function provided to release variable stats with");
 			}
+			else if (rel_persistence == RELPERSISTENCE_GLOBAL_TEMP)
+			{
+				vardata.statsTuple =
+					get_gtt_att_statistic(index->indexoid,
+										attnum,
+										false);
+				vardata.freefunc = release_gtt_statistic_cache;
+			}
 			else
 			{
 				vardata.statsTuple = SearchSysCache3(STATRELATTINH,
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 3da90cb..97240ff 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -34,6 +34,7 @@
 #include "catalog/pg_statistic.h"
 #include "catalog/pg_transform.h"
 #include "catalog/pg_type.h"
+#include "catalog/storage_gtt.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "utils/array.h"
@@ -2878,6 +2879,18 @@ get_attavgwidth(Oid relid, AttrNumber attnum)
 		if (stawidth > 0)
 			return stawidth;
 	}
+	if (get_rel_persistence(relid) == RELPERSISTENCE_GLOBAL_TEMP)
+	{
+		tp = get_gtt_att_statistic(relid, attnum, false);
+		if (!HeapTupleIsValid(tp))
+			return 0;
+
+		stawidth = ((Form_pg_statistic) GETSTRUCT(tp))->stawidth;
+		if (stawidth > 0)
+			return stawidth;
+		else
+			return 0;
+	}
 	tp = SearchSysCache3(STATRELATTINH,
 						 ObjectIdGetDatum(relid),
 						 Int16GetDatum(attnum),
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index ff70326..1cf7063 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -63,6 +63,7 @@
 #include "catalog/pg_type.h"
 #include "catalog/schemapg.h"
 #include "catalog/storage.h"
+#include "catalog/storage_gtt.h"
 #include "commands/policy.h"
 #include "commands/trigger.h"
 #include "miscadmin.h"
@@ -1127,6 +1128,24 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
 				relation->rd_islocaltemp = false;
 			}
 			break;
+		case RELPERSISTENCE_GLOBAL_TEMP:
+			{
+				BlockNumber     relpages = 0;
+				double          reltuples = 0;
+				BlockNumber     relallvisible = 0;
+
+				relation->rd_backend = BackendIdForTempRelations();
+				relation->rd_islocaltemp = false;
+				get_gtt_relstats(RelationGetRelid(relation),
+								&relpages,
+								&reltuples,
+								&relallvisible,
+								NULL, NULL);
+				relation->rd_rel->relpages = (int32)relpages;
+				relation->rd_rel->reltuples = (float4)reltuples;
+				relation->rd_rel->relallvisible = (int32)relallvisible;
+			}
+			break;
 		default:
 			elog(ERROR, "invalid relpersistence: %c",
 				 relation->rd_rel->relpersistence);
@@ -1181,6 +1200,7 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
 		case RELKIND_PARTITIONED_INDEX:
 			Assert(relation->rd_rel->relam != InvalidOid);
 			RelationInitIndexAccessInfo(relation);
+			gtt_fix_index_state(relation);
 			break;
 		case RELKIND_RELATION:
 		case RELKIND_TOASTVALUE:
@@ -2220,6 +2240,8 @@ RelationReloadIndexInfo(Relation relation)
 							   HeapTupleHeaderGetXmin(tuple->t_data));
 
 		ReleaseSysCache(tuple);
+
+		gtt_fix_index_state(relation);
 	}
 
 	/* Okay, now it's valid again */
@@ -3316,6 +3338,10 @@ RelationBuildLocalRelation(const char *relname,
 			rel->rd_backend = BackendIdForTempRelations();
 			rel->rd_islocaltemp = true;
 			break;
+		case RELPERSISTENCE_GLOBAL_TEMP:
+			rel->rd_backend = BackendIdForTempRelations();
+			rel->rd_islocaltemp = false;
+			break;
 		default:
 			elog(ERROR, "invalid relpersistence: %c", relpersistence);
 			break;
@@ -3430,6 +3456,9 @@ RelationSetNewRelfilenode(Relation relation, char persistence)
 	TransactionId freezeXid = InvalidTransactionId;
 	RelFileNode newrnode;
 
+	if (RELATION_IS_GLOBAL_TEMP(relation))
+		elog(ERROR, "global temp table does not allow setting new relfilenode");
+
 	/* Allocate a new relfilenode */
 	newrelfilenode = GetNewRelFileNode(relation->rd_rel->reltablespace, NULL,
 									   persistence);
@@ -3470,7 +3499,7 @@ RelationSetNewRelfilenode(Relation relation, char persistence)
 				/* handle these directly, at least for now */
 				SMgrRelation srel;
 
-				srel = RelationCreateStorage(newrnode, persistence);
+				srel = RelationCreateStorage(newrnode, persistence, relation);
 				smgrclose(srel);
 			}
 			break;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index dbecc00..6acf3f3 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -140,6 +140,18 @@ char	   *GUC_check_errmsg_string;
 char	   *GUC_check_errdetail_string;
 char	   *GUC_check_errhint_string;
 
+/*
+ * num = 0 means disable global temp table feature.
+ * global temp table define can still storage in catalog
+ * just can not use.
+ * num > 0 means database can management num active global temp table.
+ */
+#define	MIN_NUM_ACTIVE_GTT			0
+#define	DEFAULT_NUM_ACTIVE_GTT			1000
+#define	MAX_NUM_ACTIVE_GTT			1000000
+
+int		max_active_gtt = MIN_NUM_ACTIVE_GTT;
+
 static void do_serialize(char **destptr, Size *maxbytes, const char *fmt,...) pg_attribute_printf(3, 4);
 
 static void set_config_sourcefile(const char *name, char *sourcefile,
@@ -2047,6 +2059,15 @@ static struct config_bool ConfigureNamesBool[] =
 static struct config_int ConfigureNamesInt[] =
 {
 	{
+		{"max_active_global_temporary_table", PGC_POSTMASTER, UNGROUPED,
+			gettext_noop("max active global temporary table."),
+			NULL
+		},
+		&max_active_gtt,
+		DEFAULT_NUM_ACTIVE_GTT, MIN_NUM_ACTIVE_GTT, MAX_NUM_ACTIVE_GTT,
+		NULL, NULL, NULL
+	},
+	{
 		{"archive_timeout", PGC_SIGHUP, WAL_ARCHIVING,
 			gettext_noop("Forces a switch to the next WAL file if a "
 						 "new file has not been started within N seconds."),
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index a12c8d0..58b22ea 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -15595,6 +15595,7 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 	{
 		char	   *ftoptions = NULL;
 		char	   *srvname = NULL;
+		char		*table_type = NULL;
 
 		switch (tbinfo->relkind)
 		{
@@ -15646,9 +15647,15 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 			binary_upgrade_set_pg_class_oids(fout, q,
 											 tbinfo->dobj.catId.oid, false);
 
+		if (tbinfo->relpersistence == RELPERSISTENCE_UNLOGGED)
+			table_type = "UNLOGGED ";
+		else if (tbinfo->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+			table_type = "GLOBAL TEMPORARY ";
+		else
+			table_type = "";
+
 		appendPQExpBuffer(q, "CREATE %s%s %s",
-						  tbinfo->relpersistence == RELPERSISTENCE_UNLOGGED ?
-						  "UNLOGGED " : "",
+						  table_type,
 						  reltypename,
 						  qualrelname);
 
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 5f9a102..3e40297 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -84,7 +84,7 @@ check_and_dump_old_cluster(bool live_check)
 		start_postmaster(&old_cluster, true);
 
 	/* Extract a list of databases and tables from the old cluster */
-	get_db_and_rel_infos(&old_cluster);
+	get_db_and_rel_infos(&old_cluster, true);
 
 	init_tablespaces();
 
@@ -157,7 +157,7 @@ check_and_dump_old_cluster(bool live_check)
 void
 check_new_cluster(void)
 {
-	get_db_and_rel_infos(&new_cluster);
+	get_db_and_rel_infos(&new_cluster, false);
 
 	check_new_cluster_is_empty();
 	check_databases_are_compatible();
diff --git a/src/bin/pg_upgrade/info.c b/src/bin/pg_upgrade/info.c
index 7e524ea..371168f 100644
--- a/src/bin/pg_upgrade/info.c
+++ b/src/bin/pg_upgrade/info.c
@@ -21,7 +21,7 @@ static void report_unmatched_relation(const RelInfo *rel, const DbInfo *db,
 									  bool is_new_db);
 static void free_db_and_rel_infos(DbInfoArr *db_arr);
 static void get_db_infos(ClusterInfo *cluster);
-static void get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo);
+static void get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo, bool skip_gtt);
 static void free_rel_infos(RelInfoArr *rel_arr);
 static void print_db_infos(DbInfoArr *dbinfo);
 static void print_rel_infos(RelInfoArr *rel_arr);
@@ -304,9 +304,11 @@ print_maps(FileNameMap *maps, int n_maps, const char *db_name)
  *
  * higher level routine to generate dbinfos for the database running
  * on the given "port". Assumes that server is already running.
+ * for check object need check global temp table,
+ * for create object skip global temp table.
  */
 void
-get_db_and_rel_infos(ClusterInfo *cluster)
+get_db_and_rel_infos(ClusterInfo *cluster, bool skip_gtt)
 {
 	int			dbnum;
 
@@ -316,7 +318,7 @@ get_db_and_rel_infos(ClusterInfo *cluster)
 	get_db_infos(cluster);
 
 	for (dbnum = 0; dbnum < cluster->dbarr.ndbs; dbnum++)
-		get_rel_infos(cluster, &cluster->dbarr.dbs[dbnum]);
+		get_rel_infos(cluster, &cluster->dbarr.dbs[dbnum], skip_gtt);
 
 	if (cluster == &old_cluster)
 		pg_log(PG_VERBOSE, "\nsource databases:\n");
@@ -404,7 +406,7 @@ get_db_infos(ClusterInfo *cluster)
  * This allows later processing to match up old and new databases efficiently.
  */
 static void
-get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo)
+get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo, bool skip_gtt)
 {
 	PGconn	   *conn = connectToServer(cluster,
 									   dbinfo->db_name);
@@ -441,22 +443,46 @@ get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo)
 	 * output, so we have to copy that system table.  It's easiest to do that
 	 * by treating it as a user table.
 	 */
-	snprintf(query + strlen(query), sizeof(query) - strlen(query),
-			 "WITH regular_heap (reloid, indtable, toastheap) AS ( "
-			 "  SELECT c.oid, 0::oid, 0::oid "
-			 "  FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n "
-			 "         ON c.relnamespace = n.oid "
-			 "  WHERE relkind IN (" CppAsString2(RELKIND_RELATION) ", "
-			 CppAsString2(RELKIND_MATVIEW) ") AND "
-	/* exclude possible orphaned temp tables */
-			 "    ((n.nspname !~ '^pg_temp_' AND "
-			 "      n.nspname !~ '^pg_toast_temp_' AND "
-			 "      n.nspname NOT IN ('pg_catalog', 'information_schema', "
-			 "                        'binary_upgrade', 'pg_toast') AND "
-			 "      c.oid >= %u::pg_catalog.oid) OR "
-			 "     (n.nspname = 'pg_catalog' AND "
-			 "      relname IN ('pg_largeobject') ))), ",
-			 FirstNormalObjectId);
+	if (skip_gtt)
+	{
+		snprintf(query + strlen(query), sizeof(query) - strlen(query),
+				 "WITH regular_heap (reloid, indtable, toastheap) AS ( "
+				 "  SELECT c.oid, 0::oid, 0::oid "
+				 "  FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n "
+				 "         ON c.relnamespace = n.oid "
+				 "  WHERE relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+				 CppAsString2(RELKIND_MATVIEW) ") AND "
+		/* exclude global temp tables */
+				 "    relpersistence != " CppAsString2(RELPERSISTENCE_GLOBAL_TEMP) " AND "
+		/* exclude possible orphaned temp tables */
+				 "    ((n.nspname !~ '^pg_temp_' AND "
+				 "      n.nspname !~ '^pg_toast_temp_' AND "
+				 "      n.nspname NOT IN ('pg_catalog', 'information_schema', "
+				 "                        'binary_upgrade', 'pg_toast') AND "
+				 "      c.oid >= %u::pg_catalog.oid) OR "
+				 "     (n.nspname = 'pg_catalog' AND "
+				 "      relname IN ('pg_largeobject') ))), ",
+				 FirstNormalObjectId);
+	}
+	else
+	{
+		snprintf(query + strlen(query), sizeof(query) - strlen(query),
+				 "WITH regular_heap (reloid, indtable, toastheap) AS ( "
+				 "  SELECT c.oid, 0::oid, 0::oid "
+				 "  FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n "
+				 "         ON c.relnamespace = n.oid "
+				 "  WHERE relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+				 CppAsString2(RELKIND_MATVIEW) ") AND "
+		/* exclude possible orphaned temp tables */
+				 "    ((n.nspname !~ '^pg_temp_' AND "
+				 "      n.nspname !~ '^pg_toast_temp_' AND "
+				 "      n.nspname NOT IN ('pg_catalog', 'information_schema', "
+				 "                        'binary_upgrade', 'pg_toast') AND "
+				 "      c.oid >= %u::pg_catalog.oid) OR "
+				 "     (n.nspname = 'pg_catalog' AND "
+				 "      relname IN ('pg_largeobject') ))), ",
+				 FirstNormalObjectId);
+	}
 
 	/*
 	 * Add a CTE that collects OIDs of toast tables belonging to the tables
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 70194eb..8dd9e66 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -411,7 +411,7 @@ create_new_objects(void)
 		set_frozenxids(true);
 
 	/* update new_cluster info now that we have objects in the databases */
-	get_db_and_rel_infos(&new_cluster);
+	get_db_and_rel_infos(&new_cluster, true);
 }
 
 /*
@@ -642,7 +642,9 @@ set_frozenxids(bool minmxid_only)
 									  "UPDATE	pg_catalog.pg_class "
 									  "SET	relfrozenxid = '%u' "
 			/* only heap, materialized view, and TOAST are vacuumed */
-									  "WHERE	relkind IN ("
+									  "WHERE "
+									  " relpersistence != " CppAsString2(RELPERSISTENCE_GLOBAL_TEMP) " AND "
+									  "relkind IN ("
 									  CppAsString2(RELKIND_RELATION) ", "
 									  CppAsString2(RELKIND_MATVIEW) ", "
 									  CppAsString2(RELKIND_TOASTVALUE) ")",
@@ -653,7 +655,9 @@ set_frozenxids(bool minmxid_only)
 								  "UPDATE	pg_catalog.pg_class "
 								  "SET	relminmxid = '%u' "
 		/* only heap, materialized view, and TOAST are vacuumed */
-								  "WHERE	relkind IN ("
+								  "WHERE "
+								  " relpersistence != " CppAsString2(RELPERSISTENCE_GLOBAL_TEMP) " AND "
+								  "relkind IN ("
 								  CppAsString2(RELKIND_RELATION) ", "
 								  CppAsString2(RELKIND_MATVIEW) ", "
 								  CppAsString2(RELKIND_TOASTVALUE) ")",
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 8b90cef..d155205 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -389,7 +389,7 @@ void		check_loadable_libraries(void);
 FileNameMap *gen_db_file_maps(DbInfo *old_db,
 							  DbInfo *new_db, int *nmaps, const char *old_pgdata,
 							  const char *new_pgdata);
-void		get_db_and_rel_infos(ClusterInfo *cluster);
+void		get_db_and_rel_infos(ClusterInfo *cluster, bool skip_gtt);
 void		print_maps(FileNameMap *maps, int n,
 					   const char *db_name);
 
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index f3c7eb9..28134e2 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -3723,7 +3723,8 @@ listTables(const char *tabtypes, const char *pattern, bool verbose, bool showSys
 		if (pset.sversion >= 90100)
 		{
 			appendPQExpBuffer(&buf,
-							  ",\n  CASE c.relpersistence WHEN 'p' THEN '%s' WHEN 't' THEN '%s' WHEN 'u' THEN '%s' END as \"%s\"",
+							  ",\n  CASE c.relpersistence WHEN 'g' THEN '%s' WHEN 'p' THEN '%s' WHEN 't' THEN '%s' WHEN 'u' THEN '%s' END as \"%s\"",
+							  gettext_noop("session"),
 							  gettext_noop("permanent"),
 							  gettext_noop("temporary"),
 							  gettext_noop("unlogged"),
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index b6b08d0..16377e6 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1016,6 +1016,8 @@ static const pgsql_thing_t words_after_create[] = {
 	{"FOREIGN TABLE", NULL, NULL, NULL},
 	{"FUNCTION", NULL, NULL, Query_for_list_of_functions},
 	{"GROUP", Query_for_list_of_roles},
+	{"GLOBAL", NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE GLOBAL TEMP/TEMPORARY TABLE
+																	* ... */
 	{"INDEX", NULL, NULL, &Query_for_list_of_indexes},
 	{"LANGUAGE", Query_for_list_of_languages},
 	{"LARGE OBJECT", NULL, NULL, NULL, THING_NO_CREATE | THING_NO_DROP},
@@ -2378,6 +2380,9 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE FOREIGN DATA WRAPPER */
 	else if (Matches("CREATE", "FOREIGN", "DATA", "WRAPPER", MatchAny))
 		COMPLETE_WITH("HANDLER", "VALIDATOR", "OPTIONS");
+	/* CREATE GLOBAL TEMP/TEMPORARY*/
+	else if (Matches("CREATE", "GLOBAL"))
+		COMPLETE_WITH("TEMP", "TEMPORARY");
 
 	/* CREATE INDEX --- is allowed inside CREATE SCHEMA, so use TailMatches */
 	/* First off we complete CREATE UNIQUE with "INDEX" */
@@ -2586,6 +2591,8 @@ psql_completion(const char *text, int start, int end)
 	/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
 	else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
 		COMPLETE_WITH("SEQUENCE", "TABLE", "VIEW");
+	else if (TailMatches("CREATE", "GLOBAL", "TEMP|TEMPORARY"))
+		COMPLETE_WITH("TABLE");
 	/* Complete "CREATE UNLOGGED" with TABLE or MATVIEW */
 	else if (TailMatches("CREATE", "UNLOGGED"))
 		COMPLETE_WITH("TABLE", "MATERIALIZED VIEW");
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 78b33b2..4be89f6 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -168,6 +168,7 @@ typedef FormData_pg_class *Form_pg_class;
 #define		  RELPERSISTENCE_PERMANENT	'p' /* regular table */
 #define		  RELPERSISTENCE_UNLOGGED	'u' /* unlogged permanent table */
 #define		  RELPERSISTENCE_TEMP		't' /* temporary table */
+#define		  RELPERSISTENCE_GLOBAL_TEMP	'g' /* global temporary table */
 
 /* default selection for replica identity (primary key or nothing) */
 #define		  REPLICA_IDENTITY_DEFAULT	'd'
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 7fb574f..6f8591c 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5507,6 +5507,40 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_xact_function_self_time' },
 
+# For global temporary table
+{ oid => '4191',
+  descr => 'List local statistics for global temporary table',
+  proname => 'pg_get_gtt_statistics', provolatile => 'v', proparallel => 'u',
+  prorettype => 'record', proretset => 't', prorows => '10', proargtypes => 'oid int4 anyelement',
+  proallargtypes => '{oid,int4,anyelement,oid,int2,bool,float4,int4,float4,int2,int2,int2,int2,int2,oid,oid,oid,oid,oid,oid,oid,oid,oid,oid,_float4,_float4,_float4,_float4,_float4,anyarray,anyarray,anyarray,anyarray,anyarray}',
+  proargmodes => '{i,i,i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
+  proargnames => '{relid,att,x,starelid,staattnum,stainherit,stanullfrac,stawidth,stadistinct,stakind1,stakind2,stakind3,stakind4,stakind5,staop1,staop2,staop3,staop4,staop5,stacoll1,stacoll2,stacoll3,stacoll4,stacoll5,stanumbers1,stanumbers2,stanumbers3,stanumbers4,stanumbers5,stavalues1,stavalues2,stavalues3,stavalues4,stavalues5}',
+  prosrc => 'pg_get_gtt_statistics' },
+{ oid => '4192',
+  descr => 'List local relstats for global temporary table',
+  proname => 'pg_get_gtt_relstats', provolatile => 'v', proparallel => 'u',
+  prorettype => 'record', proretset => 't', prorows => '10', proargtypes => 'oid',
+  proallargtypes => '{oid,int4,float4,int4,xid,xid}',
+  proargmodes => '{i,o,o,o,o,o}',
+  proargnames => '{relid,relpages,reltuples,relallvisible,relfrozenxid,relminmxid}',
+  prosrc => 'pg_get_gtt_relstats' },
+{ oid => '4193',
+  descr => 'List attached pid for one global temporary table',
+  proname => 'pg_gtt_attached_pid', provolatile => 'v', proparallel => 'u',
+  prorettype => 'record', proretset => 't', prorows => '10', proargtypes => 'oid',
+  proallargtypes => '{oid,oid,int4}',
+  proargmodes => '{i,o,o}',
+  proargnames => '{relid,relid,pid}',
+  prosrc => 'pg_gtt_attached_pid' },
+{ oid => '4194',
+  descr => 'List those backends that have used global temporary table',
+  proname => 'pg_list_gtt_relfrozenxids', provolatile => 'v', proparallel => 'u',
+  prorettype => 'record', proretset => 't', prorows => '10', proargtypes => '',
+  proallargtypes => '{int4,xid}',
+  proargmodes => '{o,o}',
+  proargnames => '{pid,relfrozenxid}',
+  prosrc => 'pg_list_gtt_relfrozenxids' },
+
 { oid => '3788',
   descr => 'statistics: timestamp of the current statistics snapshot',
   proname => 'pg_stat_get_snapshot_timestamp', provolatile => 's',
diff --git a/src/include/catalog/storage.h b/src/include/catalog/storage.h
index 048003c..af48cdf 100644
--- a/src/include/catalog/storage.h
+++ b/src/include/catalog/storage.h
@@ -19,7 +19,7 @@
 #include "storage/smgr.h"
 #include "utils/relcache.h"
 
-extern SMgrRelation RelationCreateStorage(RelFileNode rnode, char relpersistence);
+extern SMgrRelation RelationCreateStorage(RelFileNode rnode, char relpersistence, Relation rel);
 extern void RelationDropStorage(Relation rel);
 extern void RelationPreserveStorage(RelFileNode rnode, bool atCommit);
 extern void RelationTruncate(Relation rel, BlockNumber nblocks);
diff --git a/src/include/catalog/storage_gtt.h b/src/include/catalog/storage_gtt.h
new file mode 100644
index 0000000..63f7241
--- /dev/null
+++ b/src/include/catalog/storage_gtt.h
@@ -0,0 +1,43 @@
+/*-------------------------------------------------------------------------
+ *
+ * storage_gtt.h
+ *	  prototypes for functions in backend/catalog/storage_gtt.c
+ *
+ * src/include/catalog/storage_gtt.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef STORAGE_GTT_H
+#define STORAGE_GTT_H
+
+#include "access/htup.h"
+#include "storage/block.h"
+#include "storage/relfilenode.h"
+#include "nodes/execnodes.h"
+#include "utils/relcache.h"
+
+extern Size active_gtt_shared_hash_size(void);
+extern void active_gtt_shared_hash_init(void);
+extern void remember_gtt_storage_info(RelFileNode rnode, Relation rel);
+extern void forget_gtt_storage_info(Oid relid, bool isCommit);
+extern bool is_other_backend_use_gtt(RelFileNode node);
+extern bool gtt_storage_attached(Oid relid);
+extern Bitmapset *copy_active_gtt_bitmap(RelFileNode node);
+extern void up_gtt_att_statistic(Oid reloid, int attnum, bool inh, int natts,
+								TupleDesc tupleDescriptor, Datum *values, bool *isnull);
+extern HeapTuple get_gtt_att_statistic(Oid reloid, int attnum, bool inh);
+extern void release_gtt_statistic_cache(HeapTuple tup);
+extern void up_gtt_relstats(Relation relation,
+							BlockNumber num_pages,
+							double num_tuples,
+							BlockNumber num_all_visible_pages,
+							TransactionId relfrozenxid,
+							TransactionId relminmxid);
+extern bool get_gtt_relstats(Oid relid, BlockNumber *relpages, double *reltuples,
+							BlockNumber *relallvisible, TransactionId *relfrozenxid,
+							TransactionId *relminmxid);
+extern void gtt_force_enable_index(Relation index);
+extern void gtt_fix_index_state(Relation index);
+extern void init_gtt_storage(CmdType operation, ResultRelInfo *resultRelInfo);
+
+#endif							/* STORAGE_H */
diff --git a/src/include/commands/sequence.h b/src/include/commands/sequence.h
index e2638ab..89a5ce4 100644
--- a/src/include/commands/sequence.h
+++ b/src/include/commands/sequence.h
@@ -65,5 +65,6 @@ extern void seq_redo(XLogReaderState *rptr);
 extern void seq_desc(StringInfo buf, XLogReaderState *rptr);
 extern const char *seq_identify(uint8 info);
 extern void seq_mask(char *pagedata, BlockNumber blkno);
+extern void gtt_init_seq(Relation rel);
 
 #endif							/* SEQUENCE_H */
diff --git a/src/include/parser/parse_relation.h b/src/include/parser/parse_relation.h
index 93f9446..14cafae 100644
--- a/src/include/parser/parse_relation.h
+++ b/src/include/parser/parse_relation.h
@@ -120,4 +120,7 @@ extern Oid	attnumTypeId(Relation rd, int attid);
 extern Oid	attnumCollationId(Relation rd, int attid);
 extern bool isQueryUsingTempRelation(Query *query);
 
+/* global temp table check */
+extern bool is_query_using_gtt(Query *query);
+
 #endif							/* PARSE_RELATION_H */
diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index 3f88683..f870e9a 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -405,6 +405,8 @@ do { \
 #define PageClearPrunable(page) \
 	(((PageHeader) (page))->pd_prune_xid = InvalidTransactionId)
 
+#define GlobalTempRelationPageIsNotInitialized(rel, page) \
+	((rel)->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP && PageIsNew(page))
 
 /* ----------------------------------------------------------------
  *		extern declarations
diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index 8fda8e4..172eae9 100644
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -220,6 +220,7 @@ typedef enum BuiltinTrancheIds
 	LWTRANCHE_TBM,
 	LWTRANCHE_PARALLEL_APPEND,
 	LWTRANCHE_SXACT,
+	LWTRANCHE_GTT_CTL,
 	LWTRANCHE_FIRST_USER_DEFINED
 }			BuiltinTrancheIds;
 
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index d217801..8adde87 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -117,6 +117,8 @@ struct PGPROC
 	Oid			tempNamespaceId;	/* OID of temp schema this backend is
 									 * using */
 
+	TransactionId session_gtt_frozenxid;	/* session level global temp table relfrozenxid */
+
 	bool		isBackgroundWorker; /* true if background worker. */
 
 	/*
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index a5c7d0c..a86f61f 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -125,4 +125,6 @@ extern void ProcArraySetReplicationSlotXmin(TransactionId xmin,
 extern void ProcArrayGetReplicationSlotXmin(TransactionId *xmin,
 											TransactionId *catalog_xmin);
 
+extern int list_all_session_gtt_frozenxids(int max_size, int *pids, uint32 *xids, int *n);
+
 #endif							/* PROCARRAY_H */
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index ce93ace..0f7262e 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -281,6 +281,10 @@ extern int	tcp_user_timeout;
 extern bool trace_sort;
 #endif
 
+/* global temporary table */
+extern int	max_active_gtt;
+/* end */
+
 /*
  * Functions exported by guc.c
  */
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 44ed04d..6b6d2da 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -57,7 +57,7 @@ typedef struct RelationData
 	struct SMgrRelationData *rd_smgr;	/* cached file handle, or NULL */
 	int			rd_refcnt;		/* reference count */
 	BackendId	rd_backend;		/* owning backend id, if temporary relation */
-	bool		rd_islocaltemp; /* rel is a temp rel of this session */
+	bool		rd_islocaltemp;	/* rel is a temp rel of this session */
 	bool		rd_isnailed;	/* rel is nailed in cache */
 	bool		rd_isvalid;		/* relcache entry is valid */
 	bool		rd_indexvalid;	/* is rd_indexlist valid? (also rd_pkindex and
@@ -277,6 +277,7 @@ typedef struct StdRdOptions
 	int			parallel_workers;	/* max number of parallel workers */
 	bool		vacuum_index_cleanup;	/* enables index vacuuming and cleanup */
 	bool		vacuum_truncate;	/* enables vacuum to truncate a relation */
+	bool		on_commit_delete_rows;	/* global temp table */
 } StdRdOptions;
 
 #define HEAP_MIN_FILLFACTOR			10
@@ -535,11 +536,13 @@ typedef struct ViewOptions
  *		True if relation's pages are stored in local buffers.
  */
 #define RelationUsesLocalBuffers(relation) \
-	((relation)->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+	((relation)->rd_rel->relpersistence == RELPERSISTENCE_TEMP || \
+	 (relation)->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 
 /*
  * RELATION_IS_LOCAL
- *		If a rel is either temp or newly created in the current transaction,
+ *		If a rel is either local temp or global temp relation
+ *		or newly created in the current transaction,
  *		it can be assumed to be accessible only to the current backend.
  *		This is typically used to decide that we can skip acquiring locks.
  *
@@ -547,6 +550,7 @@ typedef struct ViewOptions
  */
 #define RELATION_IS_LOCAL(relation) \
 	((relation)->rd_islocaltemp || \
+	 (relation)->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP || \
 	 (relation)->rd_createSubid != InvalidSubTransactionId)
 
 /*
@@ -559,6 +563,14 @@ typedef struct ViewOptions
 	((relation)->rd_rel->relpersistence == RELPERSISTENCE_TEMP && \
 	 !(relation)->rd_islocaltemp)
 
+/*
+ * RELATION_IS_TEMP
+ *		Test a rel is either local temp relation of this session
+ * 		or global temp relation.
+ */
+#define RELATION_IS_TEMP(relation) \
+	((relation)->rd_islocaltemp || \
+	 (relation)->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
 
 /*
  * RelationIsScannable
@@ -602,6 +614,17 @@ typedef struct ViewOptions
 	 RelationNeedsWAL(relation) && \
 	 !IsCatalogRelation(relation))
 
+/* global temp table implementations */
+#define RELATION_IS_GLOBAL_TEMP(relation)	((relation)->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP)
+
+#define RELATION_GTT_ON_COMMIT_DELETE(relation)	\
+	((relation)->rd_options && \
+	 ((relation)->rd_rel->relkind == RELKIND_RELATION || (relation)->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) && \
+	 (relation)->rd_rel->relpersistence == RELPERSISTENCE_GLOBAL_TEMP ? \
+	 ((StdRdOptions *) (relation)->rd_options)->on_commit_delete_rows : false)
+
+#define RelationGetRelPersistence(relation) ((relation)->rd_rel->relpersistence)
+
 /* routines in utils/cache/relcache.c */
 extern void RelationIncrementReferenceCount(Relation rel);
 extern void RelationDecrementReferenceCount(Relation rel);
diff --git a/src/test/regress/expected/gtt_clean.out b/src/test/regress/expected/gtt_clean.out
new file mode 100644
index 0000000..73d3d7b
--- /dev/null
+++ b/src/test/regress/expected/gtt_clean.out
@@ -0,0 +1,8 @@
+reset search_path;
+drop schema gtt cascade;
+NOTICE:  drop cascades to 5 other objects
+DETAIL:  drop cascades to table gtt.gtt1
+drop cascades to table gtt.gtt2
+drop cascades to table gtt.gtt3
+drop cascades to table gtt.gtt_t_kenyon
+drop cascades to table gtt.gtt_with_seq
diff --git a/src/test/regress/expected/gtt_function.out b/src/test/regress/expected/gtt_function.out
new file mode 100644
index 0000000..067393b
--- /dev/null
+++ b/src/test/regress/expected/gtt_function.out
@@ -0,0 +1,322 @@
+CREATE SCHEMA IF NOT EXISTS gtt_function;
+set search_path=gtt_function,sys;
+create global temp table gtt1(a int primary key, b text);
+create global temp table gtt_test_rename(a int primary key, b text);
+create global temp table gtt2(a int primary key, b text) on commit delete rows;
+create global temp table gtt3(a int primary key, b text) on commit PRESERVE rows;
+create global temp table tmp_t0(c0 tsvector,c1 varchar(100));
+create table tbl_inherits_parent(
+a int not null,
+b varchar(32) not null default 'Got u',
+c int check (c > 0),
+d date not null
+);
+create global temp table tbl_inherits_parent_global_temp(
+a int not null,
+b varchar(32) not null default 'Got u',
+c int check (c > 0),
+d date not null
+)on commit delete rows;
+CREATE global temp TABLE products (
+    product_no integer PRIMARY KEY,
+    name text,
+    price numeric
+);
+create global temp table gtt6(n int) with (on_commit_delete_rows='true');
+begin;
+insert into gtt6 values (9);
+-- 1 row
+select * from gtt6;
+ n 
+---
+ 9
+(1 row)
+
+commit;
+-- 0 row
+select * from gtt6;
+ n 
+---
+(0 rows)
+
+-- ERROR
+create index CONCURRENTLY idx_gtt1 on gtt1 (b);
+ERROR:  cannot create indexes on global temporary tables using concurrent mode
+-- ERROR
+cluster gtt1 using gtt1_pkey;
+ERROR:  not support cluster global temporary tables yet
+-- ERROR
+create table gtt1(a int primary key, b text) on commit delete rows;
+ERROR:  ON COMMIT can only be used on temporary tables
+-- ERROR
+alter table gtt1 SET TABLESPACE pg_default;
+ERROR:  not support alter table set tablespace on global temp table
+-- ERROR
+alter table gtt1 set ( on_commit_delete_rows='true');
+ERROR:  The global temp table does not allow modification on commit action.
+-- ERROR
+create table gtt1(a int primary key, b text) with(on_commit_delete_rows=true);
+ERROR:  The parameter on_commit_delete_rows is exclusive to the global temp table, which cannot be specified by a regular table
+-- ok
+CREATE global temp TABLE measurement (
+    logdate         date not null,
+    peaktemp        int,
+    unitsales       int
+) PARTITION BY RANGE (logdate);
+--ok
+CREATE global temp TABLE p_table01 (
+id        bigserial NOT NULL,
+cre_time  timestamp without time zone,
+note      varchar(30)
+) PARTITION BY RANGE (cre_time)
+WITH (
+OIDS = FALSE
+)on commit delete rows;
+ 
+CREATE global temp TABLE p_table01_2018
+PARTITION OF p_table01
+FOR VALUES FROM ('2018-01-01 00:00:00') TO ('2019-01-01 00:00:00') on commit delete rows;
+ 
+CREATE global temp TABLE p_table01_2017
+PARTITION OF p_table01
+FOR VALUES FROM ('2017-01-01 00:00:00') TO ('2018-01-01 00:00:00') on commit delete rows;
+begin;
+insert into p_table01 values(1,'2018-01-02 00:00:00','test1');
+insert into p_table01 values(1,'2018-01-02 00:00:00','test2');
+select count(*) from p_table01;
+ count 
+-------
+     2
+(1 row)
+
+commit;
+select count(*) from p_table01;
+ count 
+-------
+     0
+(1 row)
+
+--ok
+CREATE global temp TABLE p_table02 (
+id        bigserial NOT NULL,
+cre_time  timestamp without time zone,
+note      varchar(30)
+) PARTITION BY RANGE (cre_time)
+WITH (
+OIDS = FALSE
+)
+on commit PRESERVE rows;
+CREATE global temp TABLE p_table02_2018
+PARTITION OF p_table02
+FOR VALUES FROM ('2018-01-01 00:00:00') TO ('2019-01-01 00:00:00');
+CREATE global temp TABLE p_table02_2017
+PARTITION OF p_table02
+FOR VALUES FROM ('2017-01-01 00:00:00') TO ('2018-01-01 00:00:00');
+-- ERROR
+create global temp table tbl_inherits_partition() inherits (tbl_inherits_parent);
+ERROR:  The parent table must be global temporary table
+-- ok
+create global temp table tbl_inherits_partition() inherits (tbl_inherits_parent_global_temp) on commit delete rows;
+select relname ,relkind, relpersistence, reloptions from pg_class where relname like 'p_table0%' or  relname like 'tbl_inherits%' order by relname;
+             relname             | relkind | relpersistence |          reloptions           
+---------------------------------+---------+----------------+-------------------------------
+ p_table01                       | p       | g              | {on_commit_delete_rows=true}
+ p_table01_2017                  | r       | g              | {on_commit_delete_rows=true}
+ p_table01_2018                  | r       | g              | {on_commit_delete_rows=true}
+ p_table01_id_seq                | S       | g              | 
+ p_table02                       | p       | g              | {on_commit_delete_rows=false}
+ p_table02_2017                  | r       | g              | {on_commit_delete_rows=false}
+ p_table02_2018                  | r       | g              | {on_commit_delete_rows=false}
+ p_table02_id_seq                | S       | g              | 
+ tbl_inherits_parent             | r       | p              | 
+ tbl_inherits_parent_global_temp | r       | g              | {on_commit_delete_rows=true}
+ tbl_inherits_partition          | r       | g              | {on_commit_delete_rows=true}
+(11 rows)
+
+-- ERROR
+create global temp table gtt3(a int primary key, b text) on commit drop;
+ERROR:  global temp table not support on commit drop clause
+-- ERROR
+create global temp table gtt4(a int primary key, b text) with(on_commit_delete_rows=true) on commit delete rows;
+ERROR:  can not defeine global temp table with on commit and with clause at same time
+-- ok
+create global temp table gtt5(a int primary key, b text) with(on_commit_delete_rows=true);
+--ok
+alter table gtt_test_rename rename to gtt_test;
+-- ok
+ALTER TABLE gtt_test ADD COLUMN address varchar(30);
+-- ERROR
+CREATE TABLE orders (
+    order_id integer PRIMARY KEY,
+    product_no integer REFERENCES products (product_no),
+    quantity integer
+);
+ERROR:  constraints on permanent tables may reference only permanent tables
+-- ok
+CREATE global temp TABLE orders (
+    order_id integer PRIMARY KEY,
+    product_no integer REFERENCES products (product_no),
+    quantity integer
+)on commit delete rows;
+--ERROR
+insert into orders values(1,1,1);
+ERROR:  insert or update on table "orders" violates foreign key constraint "orders_product_no_fkey"
+DETAIL:  Key (product_no)=(1) is not present in table "products".
+--ok
+insert into products values(1,'test',1.0);
+begin;
+insert into orders values(1,1,1);
+commit;
+select count(*) from products;
+ count 
+-------
+     1
+(1 row)
+
+select count(*) from orders;
+ count 
+-------
+     0
+(1 row)
+
+-- ok
+CREATE GLOBAL TEMPORARY TABLE mytable (
+  id SERIAL PRIMARY KEY,
+  data text
+) on commit preserve rows;
+-- ok
+create global temp table gtt_seq(id int GENERATED ALWAYS AS IDENTITY (START WITH 2) primary key, a int)  on commit PRESERVE rows;
+insert into gtt_seq (a) values(1);
+insert into gtt_seq (a) values(2);
+select * from gtt_seq order by id;
+ id | a 
+----+---
+  2 | 1
+  3 | 2
+(2 rows)
+
+truncate gtt_seq;
+select * from gtt_seq order by id;
+ id | a 
+----+---
+(0 rows)
+
+insert into gtt_seq (a) values(3);
+select * from gtt_seq order by id;
+ id | a 
+----+---
+  4 | 3
+(1 row)
+
+--ERROR
+CREATE MATERIALIZED VIEW mv_gtt1 as select * from gtt1;
+ERROR:  materialized views must not use global temporary tables or views
+-- ok
+create index idx_gtt1_1 on gtt1 using hash (a);
+create index idx_tmp_t0_1 on tmp_t0 using gin (c0);
+create index idx_tmp_t0_2 on tmp_t0 using gist (c0);
+--ok
+create global temp table gt (a SERIAL,b int);
+begin;
+set transaction_read_only = true;
+insert into gt (b) values(1);
+select * from gt;
+ a | b 
+---+---
+ 1 | 1
+(1 row)
+
+commit;
+--ok
+create global temp table gt1(a int);
+insert into gt1 values(generate_series(1,100000));
+create index idx_gt1_1 on gt1 (a);
+create index idx_gt1_2 on gt1((a + 1));
+create index idx_gt1_3 on gt1((a*10),(a+a),(a-1));
+explain (costs off) select * from gt1 where a=1;
+              QUERY PLAN              
+--------------------------------------
+ Bitmap Heap Scan on gt1
+   Recheck Cond: (a = 1)
+   ->  Bitmap Index Scan on idx_gt1_1
+         Index Cond: (a = 1)
+(4 rows)
+
+explain (costs off) select * from gt1 where a=200000;
+              QUERY PLAN              
+--------------------------------------
+ Bitmap Heap Scan on gt1
+   Recheck Cond: (a = 200000)
+   ->  Bitmap Index Scan on idx_gt1_1
+         Index Cond: (a = 200000)
+(4 rows)
+
+explain (costs off) select * from gt1 where a*10=300;
+              QUERY PLAN              
+--------------------------------------
+ Bitmap Heap Scan on gt1
+   Recheck Cond: ((a * 10) = 300)
+   ->  Bitmap Index Scan on idx_gt1_3
+         Index Cond: ((a * 10) = 300)
+(4 rows)
+
+explain (costs off) select * from gt1 where a*10=3;
+              QUERY PLAN              
+--------------------------------------
+ Bitmap Heap Scan on gt1
+   Recheck Cond: ((a * 10) = 3)
+   ->  Bitmap Index Scan on idx_gt1_3
+         Index Cond: ((a * 10) = 3)
+(4 rows)
+
+analyze gt1;
+explain (costs off) select * from gt1 where a=1;
+               QUERY PLAN               
+----------------------------------------
+ Index Only Scan using idx_gt1_1 on gt1
+   Index Cond: (a = 1)
+(2 rows)
+
+explain (costs off) select * from gt1 where a=200000;
+               QUERY PLAN               
+----------------------------------------
+ Index Only Scan using idx_gt1_1 on gt1
+   Index Cond: (a = 200000)
+(2 rows)
+
+explain (costs off) select * from gt1 where a*10=300;
+            QUERY PLAN             
+-----------------------------------
+ Index Scan using idx_gt1_3 on gt1
+   Index Cond: ((a * 10) = 300)
+(2 rows)
+
+explain (costs off) select * from gt1 where a*10=3;
+            QUERY PLAN             
+-----------------------------------
+ Index Scan using idx_gt1_3 on gt1
+   Index Cond: ((a * 10) = 3)
+(2 rows)
+
+reset search_path;
+drop schema gtt_function cascade;
+NOTICE:  drop cascades to 19 other objects
+DETAIL:  drop cascades to table gtt_function.gtt1
+drop cascades to table gtt_function.gtt_test
+drop cascades to table gtt_function.gtt2
+drop cascades to table gtt_function.gtt3
+drop cascades to table gtt_function.tmp_t0
+drop cascades to table gtt_function.tbl_inherits_parent
+drop cascades to table gtt_function.tbl_inherits_parent_global_temp
+drop cascades to table gtt_function.products
+drop cascades to table gtt_function.gtt6
+drop cascades to table gtt_function.measurement
+drop cascades to table gtt_function.p_table01
+drop cascades to table gtt_function.p_table02
+drop cascades to table gtt_function.tbl_inherits_partition
+drop cascades to table gtt_function.gtt5
+drop cascades to table gtt_function.orders
+drop cascades to table gtt_function.mytable
+drop cascades to table gtt_function.gtt_seq
+drop cascades to table gtt_function.gt
+drop cascades to table gtt_function.gt1
diff --git a/src/test/regress/expected/gtt_parallel_1.out b/src/test/regress/expected/gtt_parallel_1.out
new file mode 100644
index 0000000..0646aae
--- /dev/null
+++ b/src/test/regress/expected/gtt_parallel_1.out
@@ -0,0 +1,90 @@
+set search_path=gtt,sys;
+select nextval('gtt_with_seq_c2_seq');
+ nextval 
+---------
+       1
+(1 row)
+
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+begin;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+(1 row)
+
+commit;
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+begin;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+(1 row)
+
+rollback;
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+truncate gtt1;
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+begin;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+(1 row)
+
+truncate gtt1;
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+insert into gtt1 values(1, 'test1');
+rollback;
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+begin;
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+truncate gtt1;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+(1 row)
+
+truncate gtt1;
+commit;
+select * from gtt1 order by a;
+ a | b 
+---+---
+(0 rows)
+
+reset search_path;
diff --git a/src/test/regress/expected/gtt_parallel_2.out b/src/test/regress/expected/gtt_parallel_2.out
new file mode 100644
index 0000000..b2ef23b
--- /dev/null
+++ b/src/test/regress/expected/gtt_parallel_2.out
@@ -0,0 +1,168 @@
+set search_path=gtt,sys;
+insert into gtt3 values(1, 'test1');
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+(1 row)
+
+begin;
+insert into gtt3 values(2, 'test1');
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+ 2 | test1
+(2 rows)
+
+commit;
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+ 2 | test1
+(2 rows)
+
+begin;
+insert into gtt3 values(3, 'test1');
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+ 2 | test1
+ 3 | test1
+(3 rows)
+
+rollback;
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+ 2 | test1
+(2 rows)
+
+truncate gtt3;
+select * from gtt3 order by a;
+ a | b 
+---+---
+(0 rows)
+
+insert into gtt3 values(1, 'test1');
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+(1 row)
+
+begin;
+insert into gtt3 values(2, 'test2');
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 1 | test1
+ 2 | test2
+(2 rows)
+
+truncate gtt3;
+select * from gtt3 order by a;
+ a | b 
+---+---
+(0 rows)
+
+insert into gtt3 values(3, 'test3');
+update gtt3 set a = 3 where b = 'test1';
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 3 | test3
+(1 row)
+
+rollback;
+select * from gtt3 order by a;
+ a | b 
+---+---
+(0 rows)
+
+begin;
+select * from gtt3 order by a;
+ a | b 
+---+---
+(0 rows)
+
+truncate gtt3;
+insert into gtt3 values(5, 'test5');
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 5 | test5
+(1 row)
+
+truncate gtt3;
+insert into gtt3 values(6, 'test6');
+commit;
+select * from gtt3 order by a;
+ a |   b   
+---+-------
+ 6 | test6
+(1 row)
+
+truncate gtt3;
+insert into gtt3 values(generate_series(1,100000), 'testing');
+select count(*) from gtt3;
+ count  
+--------
+ 100000
+(1 row)
+
+analyze gtt3;
+explain (COSTS FALSE) select * from gtt3 where a =300;
+             QUERY PLAN             
+------------------------------------
+ Index Scan using gtt3_pkey on gtt3
+   Index Cond: (a = 300)
+(2 rows)
+
+insert into gtt_t_kenyon select generate_series(1,2000),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God',500);
+insert into gtt_t_kenyon select generate_series(1,2),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God,Remark here!!',2000);
+insert into gtt_t_kenyon select generate_series(3,4),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God,Remark here!!',4000);
+insert into gtt_t_kenyon select generate_series(5,6),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God,Remark here!!',5500);
+select relname, pg_relation_size(oid),pg_relation_size(reltoastrelid),pg_table_size(oid),pg_indexes_size(oid),pg_total_relation_size(oid) from pg_class where relname = 'gtt_t_kenyon';
+   relname    | pg_relation_size | pg_relation_size | pg_table_size | pg_indexes_size | pg_total_relation_size 
+--------------+------------------+------------------+---------------+-----------------+------------------------
+ gtt_t_kenyon |           450560 |             8192 |        499712 |          114688 |                 614400
+(1 row)
+
+select relname from pg_class where relname = 'gtt_t_kenyon' and reltoastrelid != 0;
+   relname    
+--------------
+ gtt_t_kenyon
+(1 row)
+
+select
+c.relname, pg_relation_size(c.oid),pg_table_size(c.oid),pg_total_relation_size(c.oid)
+from
+pg_class c
+where
+c.oid in
+(
+select
+i.indexrelid as indexrelid
+from 
+pg_index i ,pg_class cc
+where cc.relname = 'gtt_t_kenyon' and cc.oid = i.indrelid
+)
+order by c.relname;
+      relname       | pg_relation_size | pg_table_size | pg_total_relation_size 
+--------------------+------------------+---------------+------------------------
+ idx_gtt_t_kenyon_1 |            65536 |         65536 |                  65536
+ idx_gtt_t_kenyon_2 |            49152 |         49152 |                  49152
+(2 rows)
+
+insert into gtt_with_seq (c1) values(1);
+select * from gtt_with_seq;
+ c1 | c2 
+----+----
+  1 |  1
+(1 row)
+
+reset search_path;
diff --git a/src/test/regress/expected/gtt_prepare.out b/src/test/regress/expected/gtt_prepare.out
new file mode 100644
index 0000000..8c0c376
--- /dev/null
+++ b/src/test/regress/expected/gtt_prepare.out
@@ -0,0 +1,10 @@
+CREATE SCHEMA IF NOT EXISTS gtt;
+set search_path=gtt,sys;
+create global temp table gtt1(a int primary key, b text) on commit delete rows;
+create global temp table gtt2(a int primary key, b text) on commit delete rows;
+create global temp table gtt3(a int primary key, b text);
+create global temp table gtt_t_kenyon(id int,vname varchar(48),remark text) on commit PRESERVE rows;
+create index idx_gtt_t_kenyon_1 on gtt_t_kenyon(id);
+create index idx_gtt_t_kenyon_2 on gtt_t_kenyon(remark);
+CREATE GLOBAL TEMPORARY TABLE gtt_with_seq(c1 bigint, c2 bigserial) on commit PRESERVE rows;
+reset search_path;
diff --git a/src/test/regress/expected/gtt_stats.out b/src/test/regress/expected/gtt_stats.out
new file mode 100644
index 0000000..0e21b30
--- /dev/null
+++ b/src/test/regress/expected/gtt_stats.out
@@ -0,0 +1,76 @@
+CREATE SCHEMA IF NOT EXISTS gtt_stats;
+set search_path=gtt_stats,sys;
+-- expect 0
+select count(*) from pg_gtt_attached_pids;
+ count 
+-------
+     0
+(1 row)
+
+-- expect 0
+select count(*) from pg_list_gtt_relfrozenxids();
+ count 
+-------
+     0
+(1 row)
+
+create global temp table gtt(a int primary key, b text) on commit PRESERVE rows;
+-- expect 0
+select count(*) from pg_gtt_attached_pids;
+ count 
+-------
+     1
+(1 row)
+
+-- expect 0
+select count(*) from pg_list_gtt_relfrozenxids();
+ count 
+-------
+     2
+(1 row)
+
+insert into gtt values(generate_series(1,10000),'test');
+-- expect 1
+select count(*) from pg_gtt_attached_pids;
+ count 
+-------
+     1
+(1 row)
+
+-- expect 2
+select count(*) from pg_list_gtt_relfrozenxids();
+ count 
+-------
+     2
+(1 row)
+
+-- expect 0
+select schemaname, tablename, relpages, reltuples, relallvisible from pg_gtt_relstats order by tablename;
+ schemaname | tablename | relpages | reltuples | relallvisible 
+------------+-----------+----------+-----------+---------------
+ gtt_stats  | gtt       |        0 |         0 |             0
+(1 row)
+
+-- expect 0
+select * from pg_gtt_stats order by tablename;
+ schemaname | tablename | attname | inherited | null_frac | avg_width | n_distinct | most_common_vals | most_common_freqs | histogram_bounds | correlation | most_common_elems | most_common_elem_freqs | elem_count_histogram 
+------------+-----------+---------+-----------+-----------+-----------+------------+------------------+-------------------+------------------+-------------+-------------------+------------------------+----------------------
+(0 rows)
+
+analyze gtt;
+select schemaname, tablename, relpages, reltuples, relallvisible from pg_gtt_relstats order by tablename;
+ schemaname | tablename | relpages | reltuples | relallvisible 
+------------+-----------+----------+-----------+---------------
+ gtt_stats  | gtt       |       55 |     10000 |             0
+(1 row)
+
+select * from pg_gtt_stats order by tablename;
+ schemaname | tablename | attname | inherited | null_frac | avg_width | n_distinct | most_common_vals | most_common_freqs |                                                                                                                                                                                                                                                histogram_bounds                                                                                                                                                                                                                                                 | correlation | most_common_elems | most_common_elem_freqs | elem_count_histogram 
+------------+-----------+---------+-----------+-----------+-----------+------------+------------------+-------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------+-------------------+------------------------+----------------------
+ gtt_stats  | gtt       | a       | f         |         0 |         4 |         -1 |                  |                   | {1,100,200,300,400,500,600,700,800,900,1000,1100,1200,1300,1400,1500,1600,1700,1800,1900,2000,2100,2200,2300,2400,2500,2600,2700,2800,2900,3000,3100,3200,3300,3400,3500,3600,3700,3800,3900,4000,4100,4200,4300,4400,4500,4600,4700,4800,4900,5000,5100,5200,5300,5400,5500,5600,5700,5800,5900,6000,6100,6200,6300,6400,6500,6600,6700,6800,6900,7000,7100,7200,7300,7400,7500,7600,7700,7800,7900,8000,8100,8200,8300,8400,8500,8600,8700,8800,8900,9000,9100,9200,9300,9400,9500,9600,9700,9800,9900,10000} |           1 |                   |                        | 
+ gtt_stats  | gtt       | b       | f         |         0 |         5 |          1 | {test}           | {1}               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |           1 |                   |                        | 
+(2 rows)
+
+reset search_path;
+drop schema gtt_stats cascade;
+NOTICE:  drop cascades to table gtt_stats.gtt
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index c730461..8a39594 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1349,6 +1349,93 @@ pg_group| SELECT pg_authid.rolname AS groname,
           WHERE (pg_auth_members.roleid = pg_authid.oid)) AS grolist
    FROM pg_authid
   WHERE (NOT pg_authid.rolcanlogin);
+pg_gtt_attached_pids| SELECT n.nspname AS schemaname,
+    c.relname AS tablename,
+    s.relid,
+    s.pid
+   FROM (pg_class c
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))),
+    LATERAL pg_gtt_attached_pid(c.oid) s(relid, pid)
+  WHERE ((c.relpersistence = 'g'::"char") AND (c.relkind = ANY (ARRAY['r'::"char", 'p'::"char"])) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
+pg_gtt_relstats| SELECT n.nspname AS schemaname,
+    c.relname AS tablename,
+    s.relpages,
+    s.reltuples,
+    s.relallvisible,
+    s.relfrozenxid,
+    s.relminmxid
+   FROM (pg_class c
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))),
+    LATERAL pg_get_gtt_relstats(c.oid) s(relpages, reltuples, relallvisible, relfrozenxid, relminmxid)
+  WHERE ((c.relpersistence = 'g'::"char") AND (c.relkind = ANY (ARRAY['r'::"char", 'p'::"char"])) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
+pg_gtt_stats| SELECT n.nspname AS schemaname,
+    c.relname AS tablename,
+    a.attname,
+    s.stainherit AS inherited,
+    s.stanullfrac AS null_frac,
+    s.stawidth AS avg_width,
+    s.stadistinct AS n_distinct,
+        CASE
+            WHEN (s.stakind1 = 1) THEN s.stavalues1
+            WHEN (s.stakind2 = 1) THEN s.stavalues2
+            WHEN (s.stakind3 = 1) THEN s.stavalues3
+            WHEN (s.stakind4 = 1) THEN s.stavalues4
+            WHEN (s.stakind5 = 1) THEN s.stavalues5
+            ELSE NULL::text[]
+        END AS most_common_vals,
+        CASE
+            WHEN (s.stakind1 = 1) THEN s.stanumbers1
+            WHEN (s.stakind2 = 1) THEN s.stanumbers2
+            WHEN (s.stakind3 = 1) THEN s.stanumbers3
+            WHEN (s.stakind4 = 1) THEN s.stanumbers4
+            WHEN (s.stakind5 = 1) THEN s.stanumbers5
+            ELSE NULL::real[]
+        END AS most_common_freqs,
+        CASE
+            WHEN (s.stakind1 = 2) THEN s.stavalues1
+            WHEN (s.stakind2 = 2) THEN s.stavalues2
+            WHEN (s.stakind3 = 2) THEN s.stavalues3
+            WHEN (s.stakind4 = 2) THEN s.stavalues4
+            WHEN (s.stakind5 = 2) THEN s.stavalues5
+            ELSE NULL::text[]
+        END AS histogram_bounds,
+        CASE
+            WHEN (s.stakind1 = 3) THEN s.stanumbers1[1]
+            WHEN (s.stakind2 = 3) THEN s.stanumbers2[1]
+            WHEN (s.stakind3 = 3) THEN s.stanumbers3[1]
+            WHEN (s.stakind4 = 3) THEN s.stanumbers4[1]
+            WHEN (s.stakind5 = 3) THEN s.stanumbers5[1]
+            ELSE NULL::real
+        END AS correlation,
+        CASE
+            WHEN (s.stakind1 = 4) THEN s.stavalues1
+            WHEN (s.stakind2 = 4) THEN s.stavalues2
+            WHEN (s.stakind3 = 4) THEN s.stavalues3
+            WHEN (s.stakind4 = 4) THEN s.stavalues4
+            WHEN (s.stakind5 = 4) THEN s.stavalues5
+            ELSE NULL::text[]
+        END AS most_common_elems,
+        CASE
+            WHEN (s.stakind1 = 4) THEN s.stanumbers1
+            WHEN (s.stakind2 = 4) THEN s.stanumbers2
+            WHEN (s.stakind3 = 4) THEN s.stanumbers3
+            WHEN (s.stakind4 = 4) THEN s.stanumbers4
+            WHEN (s.stakind5 = 4) THEN s.stanumbers5
+            ELSE NULL::real[]
+        END AS most_common_elem_freqs,
+        CASE
+            WHEN (s.stakind1 = 5) THEN s.stanumbers1
+            WHEN (s.stakind2 = 5) THEN s.stanumbers2
+            WHEN (s.stakind3 = 5) THEN s.stanumbers3
+            WHEN (s.stakind4 = 5) THEN s.stanumbers4
+            WHEN (s.stakind5 = 5) THEN s.stanumbers5
+            ELSE NULL::real[]
+        END AS elem_count_histogram
+   FROM ((pg_class c
+     JOIN pg_attribute a ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))),
+    LATERAL pg_get_gtt_statistics(c.oid, (a.attnum)::integer, ''::text) s(starelid, staattnum, stainherit, stanullfrac, stawidth, stadistinct, stakind1, stakind2, stakind3, stakind4, stakind5, staop1, staop2, staop3, staop4, staop5, stacoll1, stacoll2, stacoll3, stacoll4, stacoll5, stanumbers1, stanumbers2, stanumbers3, stanumbers4, stanumbers5, stavalues1, stavalues2, stavalues3, stavalues4, stavalues5)
+  WHERE ((c.relpersistence = 'g'::"char") AND (c.relkind = ANY (ARRAY['r'::"char", 'p'::"char"])) AND (NOT a.attisdropped) AND has_column_privilege(c.oid, a.attnum, 'select'::text) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
 pg_hba_file_rules| SELECT a.line_number,
     a.type,
     a.database,
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index d2b17dd..80e577f 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -121,3 +121,10 @@ test: fast_default
 
 # run stats by itself because its delay may be insufficient under heavy load
 test: stats
+
+# global temp table test
+test: gtt_stats
+test: gtt_function
+test: gtt_prepare
+test: gtt_parallel_1 gtt_parallel_2
+test: gtt_clean
diff --git a/src/test/regress/sql/gtt_clean.sql b/src/test/regress/sql/gtt_clean.sql
new file mode 100644
index 0000000..f3cf710
--- /dev/null
+++ b/src/test/regress/sql/gtt_clean.sql
@@ -0,0 +1,6 @@
+
+
+reset search_path;
+
+drop schema gtt cascade;
+
diff --git a/src/test/regress/sql/gtt_function.sql b/src/test/regress/sql/gtt_function.sql
new file mode 100644
index 0000000..c32c0bd
--- /dev/null
+++ b/src/test/regress/sql/gtt_function.sql
@@ -0,0 +1,217 @@
+
+CREATE SCHEMA IF NOT EXISTS gtt_function;
+
+set search_path=gtt_function,sys;
+
+create global temp table gtt1(a int primary key, b text);
+
+create global temp table gtt_test_rename(a int primary key, b text);
+
+create global temp table gtt2(a int primary key, b text) on commit delete rows;
+
+create global temp table gtt3(a int primary key, b text) on commit PRESERVE rows;
+
+create global temp table tmp_t0(c0 tsvector,c1 varchar(100));
+
+create table tbl_inherits_parent(
+a int not null,
+b varchar(32) not null default 'Got u',
+c int check (c > 0),
+d date not null
+);
+
+create global temp table tbl_inherits_parent_global_temp(
+a int not null,
+b varchar(32) not null default 'Got u',
+c int check (c > 0),
+d date not null
+)on commit delete rows;
+
+CREATE global temp TABLE products (
+    product_no integer PRIMARY KEY,
+    name text,
+    price numeric
+);
+
+create global temp table gtt6(n int) with (on_commit_delete_rows='true');
+
+begin;
+insert into gtt6 values (9);
+-- 1 row
+select * from gtt6;
+commit;
+-- 0 row
+select * from gtt6;
+
+-- ERROR
+create index CONCURRENTLY idx_gtt1 on gtt1 (b);
+
+-- ERROR
+cluster gtt1 using gtt1_pkey;
+
+-- ERROR
+create table gtt1(a int primary key, b text) on commit delete rows;
+
+-- ERROR
+alter table gtt1 SET TABLESPACE pg_default;
+
+-- ERROR
+alter table gtt1 set ( on_commit_delete_rows='true');
+
+-- ERROR
+create table gtt1(a int primary key, b text) with(on_commit_delete_rows=true);
+
+-- ok
+CREATE global temp TABLE measurement (
+    logdate         date not null,
+    peaktemp        int,
+    unitsales       int
+) PARTITION BY RANGE (logdate);
+
+--ok
+CREATE global temp TABLE p_table01 (
+id        bigserial NOT NULL,
+cre_time  timestamp without time zone,
+note      varchar(30)
+) PARTITION BY RANGE (cre_time)
+WITH (
+OIDS = FALSE
+)on commit delete rows;
+ 
+CREATE global temp TABLE p_table01_2018
+PARTITION OF p_table01
+FOR VALUES FROM ('2018-01-01 00:00:00') TO ('2019-01-01 00:00:00') on commit delete rows;
+ 
+CREATE global temp TABLE p_table01_2017
+PARTITION OF p_table01
+FOR VALUES FROM ('2017-01-01 00:00:00') TO ('2018-01-01 00:00:00') on commit delete rows;
+
+begin;
+insert into p_table01 values(1,'2018-01-02 00:00:00','test1');
+insert into p_table01 values(1,'2018-01-02 00:00:00','test2');
+select count(*) from p_table01;
+commit;
+
+select count(*) from p_table01;
+
+--ok
+CREATE global temp TABLE p_table02 (
+id        bigserial NOT NULL,
+cre_time  timestamp without time zone,
+note      varchar(30)
+) PARTITION BY RANGE (cre_time)
+WITH (
+OIDS = FALSE
+)
+on commit PRESERVE rows;
+
+CREATE global temp TABLE p_table02_2018
+PARTITION OF p_table02
+FOR VALUES FROM ('2018-01-01 00:00:00') TO ('2019-01-01 00:00:00');
+
+CREATE global temp TABLE p_table02_2017
+PARTITION OF p_table02
+FOR VALUES FROM ('2017-01-01 00:00:00') TO ('2018-01-01 00:00:00');
+
+-- ERROR
+create global temp table tbl_inherits_partition() inherits (tbl_inherits_parent);
+
+-- ok
+create global temp table tbl_inherits_partition() inherits (tbl_inherits_parent_global_temp) on commit delete rows;
+
+select relname ,relkind, relpersistence, reloptions from pg_class where relname like 'p_table0%' or  relname like 'tbl_inherits%' order by relname;
+
+-- ERROR
+create global temp table gtt3(a int primary key, b text) on commit drop;
+
+-- ERROR
+create global temp table gtt4(a int primary key, b text) with(on_commit_delete_rows=true) on commit delete rows;
+
+-- ok
+create global temp table gtt5(a int primary key, b text) with(on_commit_delete_rows=true);
+
+--ok
+alter table gtt_test_rename rename to gtt_test;
+
+-- ok
+ALTER TABLE gtt_test ADD COLUMN address varchar(30);
+
+-- ERROR
+CREATE TABLE orders (
+    order_id integer PRIMARY KEY,
+    product_no integer REFERENCES products (product_no),
+    quantity integer
+);
+
+-- ok
+CREATE global temp TABLE orders (
+    order_id integer PRIMARY KEY,
+    product_no integer REFERENCES products (product_no),
+    quantity integer
+)on commit delete rows;
+
+--ERROR
+insert into orders values(1,1,1);
+
+--ok
+insert into products values(1,'test',1.0);
+
+begin;
+insert into orders values(1,1,1);
+commit;
+
+select count(*) from products;
+select count(*) from orders;
+
+-- ok
+CREATE GLOBAL TEMPORARY TABLE mytable (
+  id SERIAL PRIMARY KEY,
+  data text
+) on commit preserve rows;
+
+-- ok
+create global temp table gtt_seq(id int GENERATED ALWAYS AS IDENTITY (START WITH 2) primary key, a int)  on commit PRESERVE rows;
+insert into gtt_seq (a) values(1);
+insert into gtt_seq (a) values(2);
+select * from gtt_seq order by id;
+truncate gtt_seq;
+select * from gtt_seq order by id;
+insert into gtt_seq (a) values(3);
+select * from gtt_seq order by id;
+
+--ERROR
+CREATE MATERIALIZED VIEW mv_gtt1 as select * from gtt1;
+
+-- ok
+create index idx_gtt1_1 on gtt1 using hash (a);
+create index idx_tmp_t0_1 on tmp_t0 using gin (c0);
+create index idx_tmp_t0_2 on tmp_t0 using gist (c0);
+
+--ok
+create global temp table gt (a SERIAL,b int);
+begin;
+set transaction_read_only = true;
+insert into gt (b) values(1);
+select * from gt;
+commit;
+
+--ok
+create global temp table gt1(a int);
+insert into gt1 values(generate_series(1,100000));
+create index idx_gt1_1 on gt1 (a);
+create index idx_gt1_2 on gt1((a + 1));
+create index idx_gt1_3 on gt1((a*10),(a+a),(a-1));
+explain (costs off) select * from gt1 where a=1;
+explain (costs off) select * from gt1 where a=200000;
+explain (costs off) select * from gt1 where a*10=300;
+explain (costs off) select * from gt1 where a*10=3;
+analyze gt1;
+explain (costs off) select * from gt1 where a=1;
+explain (costs off) select * from gt1 where a=200000;
+explain (costs off) select * from gt1 where a*10=300;
+explain (costs off) select * from gt1 where a*10=3;
+
+reset search_path;
+
+drop schema gtt_function cascade;
+
diff --git a/src/test/regress/sql/gtt_parallel_1.sql b/src/test/regress/sql/gtt_parallel_1.sql
new file mode 100644
index 0000000..d05745e
--- /dev/null
+++ b/src/test/regress/sql/gtt_parallel_1.sql
@@ -0,0 +1,44 @@
+
+
+set search_path=gtt,sys;
+
+select nextval('gtt_with_seq_c2_seq');
+
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+
+begin;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+commit;
+select * from gtt1 order by a;
+
+begin;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+rollback;
+select * from gtt1 order by a;
+
+truncate gtt1;
+select * from gtt1 order by a;
+
+begin;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+truncate gtt1;
+select * from gtt1 order by a;
+insert into gtt1 values(1, 'test1');
+rollback;
+select * from gtt1 order by a;
+
+begin;
+select * from gtt1 order by a;
+truncate gtt1;
+insert into gtt1 values(1, 'test1');
+select * from gtt1 order by a;
+truncate gtt1;
+commit;
+select * from gtt1 order by a;
+
+reset search_path;
+
diff --git a/src/test/regress/sql/gtt_parallel_2.sql b/src/test/regress/sql/gtt_parallel_2.sql
new file mode 100644
index 0000000..bf0b922
--- /dev/null
+++ b/src/test/regress/sql/gtt_parallel_2.sql
@@ -0,0 +1,79 @@
+
+
+set search_path=gtt,sys;
+
+insert into gtt3 values(1, 'test1');
+select * from gtt3 order by a;
+
+begin;
+insert into gtt3 values(2, 'test1');
+select * from gtt3 order by a;
+commit;
+select * from gtt3 order by a;
+
+begin;
+insert into gtt3 values(3, 'test1');
+select * from gtt3 order by a;
+rollback;
+select * from gtt3 order by a;
+
+truncate gtt3;
+select * from gtt3 order by a;
+
+insert into gtt3 values(1, 'test1');
+select * from gtt3 order by a;
+
+begin;
+insert into gtt3 values(2, 'test2');
+select * from gtt3 order by a;
+truncate gtt3;
+select * from gtt3 order by a;
+insert into gtt3 values(3, 'test3');
+update gtt3 set a = 3 where b = 'test1';
+select * from gtt3 order by a;
+rollback;
+select * from gtt3 order by a;
+
+begin;
+select * from gtt3 order by a;
+truncate gtt3;
+insert into gtt3 values(5, 'test5');
+select * from gtt3 order by a;
+truncate gtt3;
+insert into gtt3 values(6, 'test6');
+commit;
+select * from gtt3 order by a;
+
+truncate gtt3;
+insert into gtt3 values(generate_series(1,100000), 'testing');
+select count(*) from gtt3;
+analyze gtt3;
+explain (COSTS FALSE) select * from gtt3 where a =300;
+
+insert into gtt_t_kenyon select generate_series(1,2000),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God',500);
+insert into gtt_t_kenyon select generate_series(1,2),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God,Remark here!!',2000);
+insert into gtt_t_kenyon select generate_series(3,4),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God,Remark here!!',4000);
+insert into gtt_t_kenyon select generate_series(5,6),repeat('kenyon here'||'^_^',2),repeat('^_^ Kenyon is not God,Remark here!!',5500);
+select relname, pg_relation_size(oid),pg_relation_size(reltoastrelid),pg_table_size(oid),pg_indexes_size(oid),pg_total_relation_size(oid) from pg_class where relname = 'gtt_t_kenyon';
+select relname from pg_class where relname = 'gtt_t_kenyon' and reltoastrelid != 0;
+
+select
+c.relname, pg_relation_size(c.oid),pg_table_size(c.oid),pg_total_relation_size(c.oid)
+from
+pg_class c
+where
+c.oid in
+(
+select
+i.indexrelid as indexrelid
+from 
+pg_index i ,pg_class cc
+where cc.relname = 'gtt_t_kenyon' and cc.oid = i.indrelid
+)
+order by c.relname;
+
+insert into gtt_with_seq (c1) values(1);
+select * from gtt_with_seq;
+
+reset search_path;
+
diff --git a/src/test/regress/sql/gtt_prepare.sql b/src/test/regress/sql/gtt_prepare.sql
new file mode 100644
index 0000000..dbe84d1
--- /dev/null
+++ b/src/test/regress/sql/gtt_prepare.sql
@@ -0,0 +1,19 @@
+
+CREATE SCHEMA IF NOT EXISTS gtt;
+
+set search_path=gtt,sys;
+
+create global temp table gtt1(a int primary key, b text) on commit delete rows;
+
+create global temp table gtt2(a int primary key, b text) on commit delete rows;
+
+create global temp table gtt3(a int primary key, b text);
+
+create global temp table gtt_t_kenyon(id int,vname varchar(48),remark text) on commit PRESERVE rows;
+create index idx_gtt_t_kenyon_1 on gtt_t_kenyon(id);
+create index idx_gtt_t_kenyon_2 on gtt_t_kenyon(remark);
+
+CREATE GLOBAL TEMPORARY TABLE gtt_with_seq(c1 bigint, c2 bigserial) on commit PRESERVE rows;
+
+reset search_path;
+
diff --git a/src/test/regress/sql/gtt_stats.sql b/src/test/regress/sql/gtt_stats.sql
new file mode 100644
index 0000000..f041892
--- /dev/null
+++ b/src/test/regress/sql/gtt_stats.sql
@@ -0,0 +1,42 @@
+
+CREATE SCHEMA IF NOT EXISTS gtt_stats;
+
+set search_path=gtt_stats,sys;
+
+-- expect 0
+select count(*) from pg_gtt_attached_pids;
+
+-- expect 0
+select count(*) from pg_list_gtt_relfrozenxids();
+
+create global temp table gtt(a int primary key, b text) on commit PRESERVE rows;
+-- expect 0
+select count(*) from pg_gtt_attached_pids;
+
+-- expect 0
+select count(*) from pg_list_gtt_relfrozenxids();
+
+insert into gtt values(generate_series(1,10000),'test');
+
+-- expect 1
+select count(*) from pg_gtt_attached_pids;
+
+-- expect 2
+select count(*) from pg_list_gtt_relfrozenxids();
+
+-- expect 0
+select schemaname, tablename, relpages, reltuples, relallvisible from pg_gtt_relstats order by tablename;
+
+-- expect 0
+select * from pg_gtt_stats order by tablename;
+
+analyze gtt;
+
+select schemaname, tablename, relpages, reltuples, relallvisible from pg_gtt_relstats order by tablename;
+
+select * from pg_gtt_stats order by tablename;
+
+reset search_path;
+
+drop schema gtt_stats cascade;
+