copy_autofrozen.v359.patch

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index c910863..b891327 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2050,12 +2050,27 @@ heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid,
 	tup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
 	tup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK);
 	tup->t_data->t_infomask |= HEAP_XMAX_INVALID;
-	HeapTupleHeaderSetXmin(tup->t_data, xid);
 	HeapTupleHeaderSetCmin(tup->t_data, cid);
 	HeapTupleHeaderSetXmax(tup->t_data, 0);		/* for cleanliness */
 	tup->t_tableOid = RelationGetRelid(relation);
 
 	/*
+	 * If we are inserting into a new relation invisible as yet to other
+	 * backends and our session has no prior snapshots and no ready portals
+	 * then we can also set the hint bit for the rows we are inserting. The
+	 * last two restrictions ensure that HeapTupleSatisfiesMVCC() gives
+	 * the right answer if the current transaction inspects the data after
+	 * we load it.
+	 */
+	if (options & HEAP_INSERT_HINT_XMIN)
+	{
+		tup->t_data->t_infomask |= HEAP_XMIN_COMMITTED;
+		HeapTupleHeaderSetXmin(tup->t_data, FrozenTransactionId);
+	}
+	else
+		HeapTupleHeaderSetXmin(tup->t_data, xid);
+
+	/*
 	 * If the new tuple is too big for storage or contains already toasted
 	 * out-of-line attributes from some other relation, invoke the toaster.
 	 */
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 110480f..a34f072 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -43,6 +43,7 @@
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
+#include "utils/portal.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
 
@@ -1922,6 +1923,21 @@ CopyFrom(CopyState cstate)
 		hi_options |= HEAP_INSERT_SKIP_FSM;
 		if (!XLogIsNeeded())
 			hi_options |= HEAP_INSERT_SKIP_WAL;
+
+		if (ThereAreNoPriorRegisteredSnapshots() &&
+			ThereAreNoReadyPortals())
+		{
+			SubTransactionId	currxid = GetCurrentSubTransactionId();
+
+			/*
+			 * If the relfilenode has been created in this subtransaction
+			 * then we can further optimise the data load by setting hint
+			 * bits and pre-freezing tuples.
+			 */
+			if (cstate->rel->rd_createSubid == currxid ||
+				cstate->rel->rd_newRelfilenodeSubid == currxid)
+				hi_options |= HEAP_INSERT_HINT_XMIN;
+		}
 	}
 
 	/*
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index cfb73c1..24075db 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -1055,3 +1055,22 @@ pg_cursor(PG_FUNCTION_ARGS)
 
 	return (Datum) 0;
 }
+
+bool
+ThereAreNoReadyPortals(void)
+{
+	HASH_SEQ_STATUS status;
+	PortalHashEnt *hentry;
+
+	hash_seq_init(&status, PortalHashTable);
+
+	while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+	{
+		Portal		portal = hentry->portal;
+
+		if (portal->status == PORTAL_READY)
+			return false;
+	}
+
+	return true;
+}
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 5aebbd1..5d9e3bf 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -1183,3 +1183,12 @@ DeleteAllExportedSnapshotFiles(void)
 
 	FreeDir(s_dir);
 }
+
+bool
+ThereAreNoPriorRegisteredSnapshots(void)
+{
+	if (RegisteredSnapshots <= 1)
+		return true;
+
+	return false;
+}
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index fa38803..0381785 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -26,6 +26,7 @@
 /* "options" flag bits for heap_insert */
 #define HEAP_INSERT_SKIP_WAL	0x0001
 #define HEAP_INSERT_SKIP_FSM	0x0002
+#define HEAP_INSERT_HINT_XMIN	0x0004
 
 typedef struct BulkInsertStateData *BulkInsertState;
 
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 4833942..bd2b133 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -219,5 +219,6 @@ extern void PortalDefineQuery(Portal portal,
 extern Node *PortalListGetPrimaryStmt(List *stmts);
 extern void PortalCreateHoldStore(Portal portal);
 extern void PortalHashTableDeleteAll(void);
+extern bool ThereAreNoReadyPortals(void);
 
 #endif   /* PORTAL_H */
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index f195981..789b72e 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -46,5 +46,6 @@ extern Datum pg_export_snapshot(PG_FUNCTION_ARGS);
 extern void ImportSnapshot(const char *idstr);
 extern bool XactHasExportedSnapshots(void);
 extern void DeleteAllExportedSnapshotFiles(void);
+extern bool ThereAreNoPriorRegisteredSnapshots(void);
 
 #endif   /* SNAPMGR_H */
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 8e2bc0c..b9626e5 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -239,6 +239,70 @@ a\.
 \.b
 c\.d
 "\."
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ a
+ b
+ c
+(3 rows)
+
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+SAVEPOINT s2;
+TRUNCATE vistest;
+SAVEPOINT s3;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ j
+ k
+ l
+(3 rows)
+
+ROLLBACK TO SAVEPOINT s2;
+SELECT * FROM vistest;
+ a 
+---
+ d
+ e
+ f
+(3 rows)
+
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
+COMMIT;
+SELECT * FROM vistest;
+ a 
+---
+ x
+ y
+ z
+(3 rows)
+
+DROP TABLE vistest;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index 6322c8f..3d2c376 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -164,6 +164,45 @@ c\.d
 
 COPY testeoc TO stdout CSV;
 
+CREATE TABLE vistest (LIKE testeoc);
+BEGIN;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+a
+b
+c
+\.
+SELECT * FROM vistest;
+SAVEPOINT s1;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+d
+e
+f
+\.
+SELECT * FROM vistest;
+SAVEPOINT s2;
+TRUNCATE vistest;
+SAVEPOINT s3;
+COPY vistest FROM stdin CSV;
+j
+k
+l
+\.
+SELECT * FROM vistest;
+ROLLBACK TO SAVEPOINT s2;
+SELECT * FROM vistest;
+TRUNCATE vistest;
+COPY vistest FROM stdin CSV;
+x
+y
+z
+\.
+SELECT * FROM vistest;
+COMMIT;
+SELECT * FROM vistest;
+
+DROP TABLE vistest;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();