Fix relcache.c so that local relations (those created during

current transaction) are not flushed by shared-cache-inval reset message.
SI reset actually works now, for probably the first time in a long time.
I was able to run initdb and regression tests with a 16-element SI message
array, with a lot of NOTICE: cache state reset messages but no crashes.

diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 6f5bbb7..db685e7 100644 (file)
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.71 1999/09/06 18:13:02 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.72 1999/09/06 19:33:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1264,9 +1264,12 @@ RelationFlushRelation(Relation *relationPtr,
         */
        smgrclose(DEFAULT_SMGR, relation);
 
-       if (relation->rd_isnailed)
+       if (relation->rd_isnailed || relation->rd_myxactonly)
        {
-               /* this is a nailed special relation for bootstrapping */
+               /* Do not flush relation cache entry if it is a nailed-in system
+                * relation or it is marked transaction-local.
+                * (To delete a local relation, caller must clear rd_myxactonly!)
+                */
                return;
        }
 
@@ -1364,6 +1367,8 @@ RelationForgetRelation(Oid rid)
                        MemoryContextSwitchTo(oldcxt);
                }
 
+               relation->rd_myxactonly = false; /* so it can be flushed */
+
                RelationFlushRelation(&relation, false);
        }
 }
@@ -1454,6 +1459,9 @@ RelationIdInvalidateRelationCacheByAccessMethodId(Oid accessMethodId)
  *      Will blow away either all the cached relation descriptors or
  *      those that have a zero reference count.
  *
+ *      This is currently used only to recover from SI message buffer overflow,
+ *      so onlyFlushReferenceCountZero is always false.  We do not blow away
+ *      transaction-local relations, since they cannot be targets of SI updates.
  */
 void
 RelationCacheInvalidate(bool onlyFlushReferenceCountZero)
@@ -1461,14 +1469,17 @@ RelationCacheInvalidate(bool onlyFlushReferenceCountZero)
        HashTableWalk(RelationNameCache, (HashtFunc) RelationFlushRelation,
                                  onlyFlushReferenceCountZero);
 
-       /*
-        * nailed-in reldescs will still be in the cache... 6 hardwired heaps
-        * + 3 hardwired indices == 9 total.
-        */
        if (!onlyFlushReferenceCountZero)
        {
-               Assert(RelationNameCache->hctl->nkeys == 9);
-               Assert(RelationIdCache->hctl->nkeys == 9);
+               /*
+                * Debugging check: what's left should be transaction-local relations
+                * plus nailed-in reldescs.  There should be 6 hardwired heaps
+                * + 3 hardwired indices == 9 total.
+                */
+               int             numRels = length(newlyCreatedRelns) + 9;
+
+               Assert(RelationNameCache->hctl->nkeys == numRels);
+               Assert(RelationIdCache->hctl->nkeys == numRels);
        }
 }
 
@@ -1580,7 +1591,7 @@ RelationPurgeLocalRelation(bool xactCommitted)
                                smgrunlink(DEFAULT_SMGR, reln);
                }
 
-               reln->rd_myxactonly = FALSE;
+               reln->rd_myxactonly = false; /* so it can be flushed */
 
                if (!IsBootstrapProcessingMode())
                        RelationFlushRelation(&reln, false);