Mega-commit to make heap_open/heap_openr/heap_close take an

additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing).  Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM.  Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing).  A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long.  Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.

9 files changed, 198 insertions, 102 deletions

diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 32111347423..0535fd6278d 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/gist/gist.c,v 1.44 1999/07/19 02:06:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/gist/gist.c,v 1.45 1999/09/18 19:05:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,6 +20,7 @@
 #include "catalog/index.h"
 #include "catalog/pg_index.h"
 #include "executor/executor.h"
+#include "miscadmin.h"
 #include "utils/syscache.h"
 
 
@@ -88,8 +89,6 @@ gistbuild(Relation heap,
 	TupleTableSlot *slot;
 
 #endif
-	Oid			hrelid,
-				irelid;
 	Node	   *pred,
 			   *oldPred;
 	GISTSTATE	giststate;
@@ -271,28 +270,31 @@ gistbuild(Relation heap,
 	}
 
 	/*
-	 * Since we just inted the tuples in the heap, we update its stats in
-	 * pg_relation to guarantee that the planner takes advantage of the
-	 * index we just created.  UpdateStats() does a
-	 * CommandinterIncrement(), which flushes changed entries from the
-	 * system relcache.  The act of constructing an index changes these
-	 * heap and index tuples in the system catalogs, so they need to be
-	 * flushed.  We close them to guarantee that they will be.
+	 * Since we just counted the tuples in the heap, we update its stats
+	 * in pg_class to guarantee that the planner takes advantage of the
+	 * index we just created.  But, only update statistics during
+	 * normal index definitions, not for indices on system catalogs
+	 * created during bootstrap processing.  We must close the relations
+	 * before updating statistics to guarantee that the relcache entries
+	 * are flushed when we increment the command counter in UpdateStats().
+	 * But we do not release any locks on the relations; those will be
+	 * held until end of transaction.
 	 */
-
-	hrelid = RelationGetRelid(heap);
-	irelid = RelationGetRelid(index);
-	heap_close(heap);
-	index_close(index);
-
-	UpdateStats(hrelid, nh, true);
-	UpdateStats(irelid, ni, false);
-
-	if (oldPred != NULL)
+	if (IsNormalProcessingMode())
 	{
-		if (ni == nh)
-			pred = NULL;
-		UpdateIndexPredicate(irelid, oldPred, pred);
+		Oid		hrelid = RelationGetRelid(heap);
+		Oid		irelid = RelationGetRelid(index);
+
+		heap_close(heap, NoLock);
+		index_close(index);
+		UpdateStats(hrelid, nh, true);
+		UpdateStats(irelid, ni, false);
+		if (oldPred != NULL)
+		{
+			if (ni == nh)
+				pred = NULL;
+			UpdateIndexPredicate(irelid, oldPred, pred);
+		}
 	}
 
 	/* be tidy */
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index 1130367b65d..6e729008e85 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hash.c,v 1.30 1999/07/17 20:16:38 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hash.c,v 1.31 1999/09/18 19:05:52 tgl Exp $
  *
  * NOTES
  *	  This file contains only the public interface routines.
@@ -66,8 +66,6 @@ hashbuild(Relation heap,
 	TupleTableSlot *slot;
 
 #endif
-	Oid			hrelid,
-				irelid;
 	Node	   *pred,
 			   *oldPred;
 
@@ -232,17 +230,20 @@ hashbuild(Relation heap,
 	/*
 	 * Since we just counted the tuples in the heap, we update its stats
 	 * in pg_class to guarantee that the planner takes advantage of the
-	 * index we just created. Finally, only update statistics during
+	 * index we just created.  But, only update statistics during
 	 * normal index definitions, not for indices on system catalogs
 	 * created during bootstrap processing.  We must close the relations
-	 * before updatings statistics to guarantee that the relcache entries
+	 * before updating statistics to guarantee that the relcache entries
 	 * are flushed when we increment the command counter in UpdateStats().
+	 * But we do not release any locks on the relations; those will be
+	 * held until end of transaction.
 	 */
 	if (IsNormalProcessingMode())
 	{
-		hrelid = RelationGetRelid(heap);
-		irelid = RelationGetRelid(index);
-		heap_close(heap);
+		Oid		hrelid = RelationGetRelid(heap);
+		Oid		irelid = RelationGetRelid(index);
+
+		heap_close(heap, NoLock);
 		index_close(index);
 		UpdateStats(hrelid, nhtups, true);
 		UpdateStats(irelid, nitups, false);
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index d8dc24c41f0..092a23cc0ec 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.53 1999/07/19 07:07:18 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.54 1999/09/18 19:05:58 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -486,15 +486,20 @@ heapgettup(Relation relation,
 /* ----------------
  *		heap_open - open a heap relation by relationId
  *
- *		presently the relcache routines do all the work we need
- *		to open/close heap relations.
+ *		If lockmode is "NoLock", no lock is obtained on the relation,
+ *		and the caller must check for a NULL return value indicating
+ *		that no such relation exists.
+ *		Otherwise, an error is raised if the relation does not exist,
+ *		and the specified kind of lock is obtained on the relation.
  * ----------------
  */
 Relation
-heap_open(Oid relationId)
+heap_open(Oid relationId, LOCKMODE lockmode)
 {
 	Relation	r;
 
+	Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
+
 	/* ----------------
 	 *	increment access statistics
 	 * ----------------
@@ -502,26 +507,41 @@ heap_open(Oid relationId)
 	IncrHeapAccessStat(local_open);
 	IncrHeapAccessStat(global_open);
 
-	r = (Relation) RelationIdGetRelation(relationId);
+	/* The relcache does all the real work... */
+	r = RelationIdGetRelation(relationId);
 
+	/* Under no circumstances will we return an index as a relation. */
 	if (RelationIsValid(r) && r->rd_rel->relkind == RELKIND_INDEX)
 		elog(ERROR, "%s is an index relation", r->rd_rel->relname.data);
 
+	if (lockmode == NoLock)
+		return r;				/* caller must check RelationIsValid! */
+
+	if (! RelationIsValid(r))
+		elog(ERROR, "Relation %u does not exist", relationId);
+
+	LockRelation(r, lockmode);
+
 	return r;
 }
 
 /* ----------------
  *		heap_openr - open a heap relation by name
  *
- *		presently the relcache routines do all the work we need
- *		to open/close heap relations.
+ *		If lockmode is "NoLock", no lock is obtained on the relation,
+ *		and the caller must check for a NULL return value indicating
+ *		that no such relation exists.
+ *		Otherwise, an error is raised if the relation does not exist,
+ *		and the specified kind of lock is obtained on the relation.
  * ----------------
  */
 Relation
-heap_openr(char *relationName)
+heap_openr(char *relationName, LOCKMODE lockmode)
 {
 	Relation	r;
 
+	Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
+
 	/* ----------------
 	 *	increment access statistics
 	 * ----------------
@@ -529,24 +549,37 @@ heap_openr(char *relationName)
 	IncrHeapAccessStat(local_openr);
 	IncrHeapAccessStat(global_openr);
 
+	/* The relcache does all the real work... */
 	r = RelationNameGetRelation(relationName);
 
+	/* Under no circumstances will we return an index as a relation. */
 	if (RelationIsValid(r) && r->rd_rel->relkind == RELKIND_INDEX)
 		elog(ERROR, "%s is an index relation", r->rd_rel->relname.data);
 
+	if (lockmode == NoLock)
+		return r;				/* caller must check RelationIsValid! */
+
+	if (! RelationIsValid(r))
+		elog(ERROR, "Relation '%s' does not exist", relationName);
+
+	LockRelation(r, lockmode);
+
 	return r;
 }
 
 /* ----------------
  *		heap_close - close a heap relation
  *
- *		presently the relcache routines do all the work we need
- *		to open/close heap relations.
+ *		If lockmode is not "NoLock", we first release the specified lock.
+ *		Note that it is often sensible to hold a lock beyond heap_close;
+ *		in that case, the lock is released automatically at xact end.
  * ----------------
  */
 void
-heap_close(Relation relation)
+heap_close(Relation relation, LOCKMODE lockmode)
 {
+	Assert(lockmode >= NoLock && lockmode < MAX_LOCKMODES);
+
 	/* ----------------
 	 *	increment access statistics
 	 * ----------------
@@ -554,6 +587,10 @@ heap_close(Relation relation)
 	IncrHeapAccessStat(local_close);
 	IncrHeapAccessStat(global_close);
 
+	if (lockmode != NoLock)
+		UnlockRelation(relation, lockmode);
+
+	/* The relcache does the real work... */
 	RelationClose(relation);
 }
 
@@ -582,15 +619,9 @@ heap_beginscan(Relation relation,
 	 *	sanity checks
 	 * ----------------
 	 */
-	if (RelationIsValid(relation) == false)
+	if (! RelationIsValid(relation))
 		elog(ERROR, "heap_beginscan: !RelationIsValid(relation)");
 
-	LockRelation(relation, AccessShareLock);
-
-	/* XXX someday assert SelfTimeQual if relkind == RELKIND_UNCATALOGED */
-	if (relation->rd_rel->relkind == RELKIND_UNCATALOGED)
-		snapshot = SnapshotSelf;
-
 	/* ----------------
 	 *	increment relation ref count while scanning relation
 	 * ----------------
@@ -598,6 +629,20 @@ heap_beginscan(Relation relation,
 	RelationIncrementReferenceCount(relation);
 
 	/* ----------------
+	 *	Acquire AccessShareLock for the duration of the scan
+	 *
+	 *	Note: we could get an SI inval message here and consequently have
+	 *	to rebuild the relcache entry.  The refcount increment above
+	 *	ensures that we will rebuild it and not just flush it...
+	 * ----------------
+	 */
+	LockRelation(relation, AccessShareLock);
+
+	/* XXX someday assert SelfTimeQual if relkind == RELKIND_UNCATALOGED */
+	if (relation->rd_rel->relkind == RELKIND_UNCATALOGED)
+		snapshot = SnapshotSelf;
+
+	/* ----------------
 	 *	allocate and initialize scan descriptor
 	 * ----------------
 	 */
@@ -684,14 +729,18 @@ heap_endscan(HeapScanDesc scan)
 	unpinscan(scan);
 
 	/* ----------------
+	 *	Release AccessShareLock acquired by heap_beginscan()
+	 * ----------------
+	 */
+	UnlockRelation(scan->rs_rd, AccessShareLock);
+
+	/* ----------------
 	 *	decrement relation reference count and free scan descriptor storage
 	 * ----------------
 	 */
 	RelationDecrementReferenceCount(scan->rs_rd);
 
-	UnlockRelation(scan->rs_rd, AccessShareLock);
-
-	pfree(scan);				/* XXX */
+	pfree(scan);
 }
 
 /* ----------------
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index 869e5e1e690..6ad242c0c39 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/index/indexam.c,v 1.35 1999/07/16 04:58:28 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/index/indexam.c,v 1.36 1999/09/18 19:06:04 tgl Exp $
  *
  * INTERFACE ROUTINES
  *		index_open		- open an index relation by relationId
@@ -129,26 +129,49 @@
  *		index_open - open an index relation by relationId
  *
  *		presently the relcache routines do all the work we need
- *		to open/close index relations.
+ *		to open/close index relations.  However, callers of index_open
+ *		expect it to succeed, so we need to check for a failure return.
+ *
+ *		Note: we acquire no lock on the index.  An AccessShareLock is
+ *		acquired by index_beginscan (and released by index_endscan).
  * ----------------
  */
 Relation
 index_open(Oid relationId)
 {
-	return RelationIdGetRelation(relationId);
+	Relation	r;
+
+	r = RelationIdGetRelation(relationId);
+
+	if (! RelationIsValid(r))
+		elog(ERROR, "Index %u does not exist", relationId);
+
+	if (r->rd_rel->relkind != RELKIND_INDEX)
+		elog(ERROR, "%s is not an index relation", r->rd_rel->relname.data);
+
+	return r;
 }
 
 /* ----------------
  *		index_openr - open a index relation by name
  *
- *		presently the relcache routines do all the work we need
- *		to open/close index relations.
+ *		As above, but lookup by name instead of OID.
  * ----------------
  */
 Relation
 index_openr(char *relationName)
 {
-	return RelationNameGetRelation(relationName);
+	Relation	r;
+
+	r = RelationNameGetRelation(relationName);
+
+	if (! RelationIsValid(r))
+		elog(ERROR, "Index '%s' does not exist", relationName);
+
+	if (r->rd_rel->relkind != RELKIND_INDEX)
+		elog(ERROR, "%s is not an index relation", r->rd_rel->relname.data);
+
+	return r;
 }
 
 /* ----------------
@@ -223,6 +246,16 @@ index_beginscan(Relation relation,
 	RELATION_CHECKS;
 	GET_REL_PROCEDURE(beginscan, ambeginscan);
 
+	RelationIncrementReferenceCount(relation);
+
+	/* ----------------
+	 *	Acquire AccessShareLock for the duration of the scan
+	 *
+	 *	Note: we could get an SI inval message here and consequently have
+	 *	to rebuild the relcache entry.  The refcount increment above
+	 *	ensures that we will rebuild it and not just flush it...
+	 * ----------------
+	 */
 	LockRelation(relation, AccessShareLock);
 
 	scandesc = (IndexScanDesc)
@@ -260,7 +293,11 @@ index_endscan(IndexScanDesc scan)
 
 	fmgr(procedure, scan);
 
+	/* Release lock and refcount acquired by index_beginscan */
+
 	UnlockRelation(scan->relation, AccessShareLock);
+
+	RelationDecrementReferenceCount(scan->relation);
 }
 
 /* ----------------
diff --git a/src/backend/access/index/istrat.c b/src/backend/access/index/istrat.c
index 1cdaadbc0c3..cab6e584609 100644
--- a/src/backend/access/index/istrat.c
+++ b/src/backend/access/index/istrat.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/index/Attic/istrat.c,v 1.35 1999/07/16 04:58:28 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/index/Attic/istrat.c,v 1.36 1999/09/18 19:06:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -558,7 +558,7 @@ IndexSupportInitialize(IndexStrategy indexStrategy,
 							   F_OIDEQ,
 							   ObjectIdGetDatum(indexObjectId));
 
-		relation = heap_openr(IndexRelationName);
+		relation = heap_openr(IndexRelationName, AccessShareLock);
 		scan = heap_beginscan(relation, false, SnapshotNow, 1, entry);
 		tuple = heap_getnext(scan, 0);
 	}
@@ -591,7 +591,7 @@ IndexSupportInitialize(IndexStrategy indexStrategy,
 	if (IsBootstrapProcessingMode())
 	{
 		heap_endscan(scan);
-		heap_close(relation);
+		heap_close(relation, AccessShareLock);
 	}
 
 	/* if support routines exist for this access method, load them */
@@ -604,7 +604,8 @@ IndexSupportInitialize(IndexStrategy indexStrategy,
 		ScanKeyEntryInitialize(&entry[1], 0, Anum_pg_amproc_amopclaid,
 							   F_OIDEQ, 0);
 
-		relation = heap_openr(AccessMethodProcedureRelationName);
+		relation = heap_openr(AccessMethodProcedureRelationName,
+							  AccessShareLock);
 
 		for (attributeNumber = 1; attributeNumber <= maxAttributeNumber;
 			 attributeNumber++)
@@ -631,7 +632,7 @@ IndexSupportInitialize(IndexStrategy indexStrategy,
 
 			heap_endscan(scan);
 		}
-		heap_close(relation);
+		heap_close(relation, AccessShareLock);
 	}
 
 	ScanKeyEntryInitialize(&entry[0], 0,
@@ -643,8 +644,8 @@ IndexSupportInitialize(IndexStrategy indexStrategy,
 						   Anum_pg_amop_amopclaid,
 						   F_OIDEQ, 0);
 
-	relation = heap_openr(AccessMethodOperatorRelationName);
-	operatorRelation = heap_openr(OperatorRelationName);
+	relation = heap_openr(AccessMethodOperatorRelationName, AccessShareLock);
+	operatorRelation = heap_openr(OperatorRelationName, AccessShareLock);
 
 	for (attributeNumber = maxAttributeNumber; attributeNumber > 0;
 		 attributeNumber--)
@@ -676,8 +677,8 @@ IndexSupportInitialize(IndexStrategy indexStrategy,
 		heap_endscan(scan);
 	}
 
-	heap_close(operatorRelation);
-	heap_close(relation);
+	heap_close(operatorRelation, AccessShareLock);
+	heap_close(relation, AccessShareLock);
 }
 
 /* ----------------
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index c97273f10f0..11f527fc3ba 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.45 1999/07/17 20:16:43 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.46 1999/09/18 19:06:10 tgl Exp $
  *
  * NOTES
  *	  This file contains only the public interface routines.
@@ -74,8 +74,6 @@ btbuild(Relation heap,
 	TupleTableSlot *slot = (TupleTableSlot *) NULL;
 
 #endif
-	Oid			hrelid,
-				irelid;
 	Node	   *pred,
 			   *oldPred;
 	void	   *spool = (void *) NULL;
@@ -301,17 +299,20 @@ btbuild(Relation heap,
 	/*
 	 * Since we just counted the tuples in the heap, we update its stats
 	 * in pg_class to guarantee that the planner takes advantage of the
-	 * index we just created. Finally, only update statistics during
+	 * index we just created.  But, only update statistics during
 	 * normal index definitions, not for indices on system catalogs
 	 * created during bootstrap processing.  We must close the relations
-	 * before updatings statistics to guarantee that the relcache entries
+	 * before updating statistics to guarantee that the relcache entries
 	 * are flushed when we increment the command counter in UpdateStats().
+	 * But we do not release any locks on the relations; those will be
+	 * held until end of transaction.
 	 */
 	if (IsNormalProcessingMode())
 	{
-		hrelid = RelationGetRelid(heap);
-		irelid = RelationGetRelid(index);
-		heap_close(heap);
+		Oid		hrelid = RelationGetRelid(heap);
+		Oid		irelid = RelationGetRelid(index);
+
+		heap_close(heap, NoLock);
 		index_close(index);
 		UpdateStats(hrelid, nhtups, true);
 		UpdateStats(irelid, nitups, false);
diff --git a/src/backend/access/rtree/rtree.c b/src/backend/access/rtree/rtree.c
index 37da716df1d..133bbdbc032 100644
--- a/src/backend/access/rtree/rtree.c
+++ b/src/backend/access/rtree/rtree.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtree.c,v 1.36 1999/07/17 20:16:45 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/rtree/Attic/rtree.c,v 1.37 1999/09/18 19:06:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,6 +19,7 @@
 #include "access/rtree.h"
 #include "catalog/index.h"
 #include "executor/executor.h"
+#include "miscadmin.h"
 #include "utils/geo_decls.h"
 
 
@@ -89,8 +90,6 @@ rtbuild(Relation heap,
 	TupleTableSlot *slot;
 
 #endif
-	Oid			hrelid,
-				irelid;
 	Node	   *pred,
 			   *oldPred;
 	RTSTATE		rtState;
@@ -248,27 +247,30 @@ rtbuild(Relation heap,
 
 	/*
 	 * Since we just counted the tuples in the heap, we update its stats
-	 * in pg_relation to guarantee that the planner takes advantage of the
-	 * index we just created.  UpdateStats() does a
-	 * CommandCounterIncrement(), which flushes changed entries from the
-	 * system relcache.  The act of constructing an index changes these
-	 * heap and index tuples in the system catalogs, so they need to be
-	 * flushed.  We close them to guarantee that they will be.
+	 * in pg_class to guarantee that the planner takes advantage of the
+	 * index we just created.  But, only update statistics during
+	 * normal index definitions, not for indices on system catalogs
+	 * created during bootstrap processing.  We must close the relations
+	 * before updating statistics to guarantee that the relcache entries
+	 * are flushed when we increment the command counter in UpdateStats().
+	 * But we do not release any locks on the relations; those will be
+	 * held until end of transaction.
 	 */
-
-	hrelid = RelationGetRelid(heap);
-	irelid = RelationGetRelid(index);
-	heap_close(heap);
-	index_close(index);
-
-	UpdateStats(hrelid, nh, true);
-	UpdateStats(irelid, ni, false);
-
-	if (oldPred != NULL)
+	if (IsNormalProcessingMode())
 	{
-		if (ni == nh)
-			pred = NULL;
-		UpdateIndexPredicate(irelid, oldPred, pred);
+		Oid		hrelid = RelationGetRelid(heap);
+		Oid		irelid = RelationGetRelid(index);
+
+		heap_close(heap, NoLock);
+		index_close(index);
+		UpdateStats(hrelid, nh, true);
+		UpdateStats(irelid, ni, false);
+		if (oldPred != NULL)
+		{
+			if (ni == nh)
+				pred = NULL;
+			UpdateIndexPredicate(irelid, oldPred, pred);
+		}
 	}
 
 	/* be tidy */
diff --git a/src/backend/access/transam/transam.c b/src/backend/access/transam/transam.c
index 1f44fb357ac..b26243b4257 100644
--- a/src/backend/access/transam/transam.c
+++ b/src/backend/access/transam/transam.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/transam.c,v 1.31 1999/08/08 20:12:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/transam.c,v 1.32 1999/09/18 19:06:21 tgl Exp $
  *
  * NOTES
  *	  This file contains the high level access-method interface to the
@@ -405,8 +405,11 @@ InitializeTransactionLog(void)
 	 *	 (these are created by amiint so they are guaranteed to exist)
 	 * ----------------
 	 */
-	logRelation = heap_openr(LogRelationName);
-	VariableRelation = heap_openr(VariableRelationName);
+	logRelation = heap_openr(LogRelationName, NoLock);
+	Assert(logRelation != NULL);
+	VariableRelation = heap_openr(VariableRelationName, NoLock);
+	Assert(VariableRelation != NULL);
+
 	/* ----------------
 	 *	 XXX TransactionLogUpdate requires that LogRelation
 	 *	 is valid so we temporarily set it so we can initialize
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 135912e97de..989b506bb7f 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.24 1999/07/15 23:03:03 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.25 1999/09/18 19:06:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -441,7 +441,7 @@ GetNewObjectId(Oid *oid_return) /* place to return the new object id */
 		 * ----------------
 		 */
 		if (!RelationIsValid(VariableRelation))
-			VariableRelation = heap_openr(VariableRelationName);
+			VariableRelation = heap_openr(VariableRelationName, NoLock);
 
 		/* ----------------
 		 *		get a new block of prefetched object ids.