Fix subtransaction behavior for large objects, temp namespace, files,

password/group files.  Also allow read-only subtransactions of a read-write
parent, but not vice versa.  These are the reasonably noncontroversial
parts of Alvaro's recent mop-up patch, plus further work on large objects
to minimize use of the TopTransactionResourceOwner.

3 files changed, 67 insertions, 19 deletions

diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
index e54a74fae4b..946bd0c9eb7 100644
--- a/src/backend/utils/cache/inval.c
+++ b/src/backend/utils/cache/inval.c
@@ -80,7 +80,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/inval.c,v 1.63 2004/07/01 00:51:17 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/inval.c,v 1.64 2004/07/28 14:23:29 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -678,7 +678,7 @@ AtEOXact_Inval(bool isCommit)
 }
 
 /*
- * AtSubEOXact_Inval
+ * AtEOSubXact_Inval
  *		Process queued-up invalidation messages at end of subtransaction.
  *
  * If isCommit, process CurrentCmdInvalidMsgs if any (there probably aren't),
@@ -695,7 +695,7 @@ AtEOXact_Inval(bool isCommit)
  * (if aborting).
  */
 void
-AtSubEOXact_Inval(bool isCommit)
+AtEOSubXact_Inval(bool isCommit)
 {
 	TransInvalidationInfo *myInfo = transInvalInfo;
 
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index b9865462a4e..22df3effc32 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <[email protected]>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.224 2004/07/24 19:51:23 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.225 2004/07/28 14:23:29 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -5436,10 +5436,15 @@ assign_log_stats(bool newval, bool doit, GucSource source)
 static bool
 assign_transaction_read_only(bool newval, bool doit, GucSource source)
 {
-	if (doit && source >= PGC_S_INTERACTIVE && IsSubTransaction())
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("cannot set transaction read only mode inside a subtransaction")));
+	/* Can't go to r/w mode inside a r/o transaction */
+	if (newval == false && XactReadOnly && IsSubTransaction())
+	{
+		if (source >= PGC_S_INTERACTIVE)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("cannot set transaction read-write mode inside a read-only transaction")));
+		return false;
+	}
 	return true;
 }
 
diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c
index 446ee4b72c5..d1a7179484e 100644
--- a/src/backend/utils/time/tqual.c
+++ b/src/backend/utils/time/tqual.c
@@ -16,7 +16,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.73 2004/07/01 00:51:33 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/time/tqual.c,v 1.74 2004/07/28 14:23:30 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -118,7 +118,10 @@ HeapTupleSatisfiesItself(HeapTupleHeader tuple)
 
 			/* deleting subtransaction aborted */
 			if (TransactionIdDidAbort(HeapTupleHeaderGetXmax(tuple)))
+			{
+				tuple->t_infomask |= HEAP_XMAX_INVALID;
 				return true;
+			}
 
 			Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
 
@@ -268,7 +271,10 @@ HeapTupleSatisfiesNow(HeapTupleHeader tuple)
 
 			/* deleting subtransaction aborted */
 			if (TransactionIdDidAbort(HeapTupleHeaderGetXmax(tuple)))
+			{
+				tuple->t_infomask |= HEAP_XMAX_INVALID;
 				return true;
+			}
 
 			Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
 
@@ -452,7 +458,10 @@ HeapTupleSatisfiesUpdate(HeapTupleHeader tuple, CommandId curcid)
 
 			/* deleting subtransaction aborted */
 			if (TransactionIdDidAbort(HeapTupleHeaderGetXmax(tuple)))
+			{
+				tuple->t_infomask |= HEAP_XMAX_INVALID;
 				return HeapTupleMayBeUpdated;
+			}
 
 			Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
 
@@ -590,7 +599,10 @@ HeapTupleSatisfiesDirty(HeapTupleHeader tuple)
 
 			/* deleting subtransaction aborted */
 			if (TransactionIdDidAbort(HeapTupleHeaderGetXmax(tuple)))
+			{
+				tuple->t_infomask |= HEAP_XMAX_INVALID;
 				return true;
+			}
 
 			Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
 
@@ -732,7 +744,10 @@ HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot)
 			/* deleting subtransaction aborted */
 			/* FIXME -- is this correct w.r.t. the cmax of the tuple? */
 			if (TransactionIdDidAbort(HeapTupleHeaderGetXmax(tuple)))
+			{
+				tuple->t_infomask |= HEAP_XMAX_INVALID;
 				return true;
+			}
 
 			Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
 
@@ -757,21 +772,36 @@ HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot)
 	/*
 	 * By here, the inserting transaction has committed - have to check
 	 * when...
+	 *
+	 * Note that the provided snapshot contains only top-level XIDs, so
+	 * we have to convert a subxact XID to its parent for comparison.
+	 * However, we can make first-pass range checks with the given XID,
+	 * because a subxact with XID < xmin has surely also got a parent with
+	 * XID < xmin, while one with XID >= xmax must belong to a parent that
+	 * was not yet committed at the time of this snapshot.
 	 */
 	if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmin(tuple),
 									 snapshot->xmin))
 	{
-		uint32		i;
+		TransactionId parentXid;
 
 		if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmin(tuple),
 										 snapshot->xmax))
 			return false;
 
-		for (i = 0; i < snapshot->xcnt; i++)
+		parentXid = SubTransGetTopmostTransaction(HeapTupleHeaderGetXmin(tuple));
+
+		if (TransactionIdFollowsOrEquals(parentXid, snapshot->xmin))
 		{
-			if (SubTransXidsHaveCommonAncestor(HeapTupleHeaderGetXmin(tuple),
-									snapshot->xip[i]))
-				return false;
+			uint32		i;
+
+			/* no point in checking parentXid against xmax here */
+
+			for (i = 0; i < snapshot->xcnt; i++)
+			{
+				if (TransactionIdEquals(parentXid, snapshot->xip[i]))
+					return false;
+			}
 		}
 	}
 
@@ -804,18 +834,31 @@ HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot)
 
 	/*
 	 * OK, the deleting transaction committed too ... but when?
+	 *
+	 * See notes for the similar tests on tuple xmin, above.
 	 */
-	if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmax(tuple), snapshot->xmin))
+	if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmax(tuple),
+									 snapshot->xmin))
 	{
-		uint32		i;
+		TransactionId parentXid;
 
 		if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmax(tuple),
 										 snapshot->xmax))
 			return true;
-		for (i = 0; i < snapshot->xcnt; i++)
+
+		parentXid = SubTransGetTopmostTransaction(HeapTupleHeaderGetXmax(tuple));
+
+		if (TransactionIdFollowsOrEquals(parentXid, snapshot->xmin))
 		{
-			if (SubTransXidsHaveCommonAncestor(HeapTupleHeaderGetXmax(tuple), snapshot->xip[i]))
-				return true;
+			uint32		i;
+
+			/* no point in checking parentXid against xmax here */
+
+			for (i = 0; i < snapshot->xcnt; i++)
+			{
+				if (TransactionIdEquals(parentXid, snapshot->xip[i]))
+					return true;
+			}
 		}
 	}