Fix from Jan for vacuum statistics loss.

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 405356414e16cfcf61f6e9894a23e1f9aed425e5..34ca9fa073a0f618438e833ae189ce4b2d03a6fb 100644 (file)
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.89 1998/10/23 01:02:08 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.90 1998/10/23 16:49:24 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1792,8 +1792,16 @@ vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *
                        /* overwrite the existing statistics in the tuple */
                        if (VacAttrStatsEqValid(stats))
                        {
+                               Buffer          abuffer;
 
+                               /*
+                                * We manipulate the heap tuple in the
+                                * buffer, so we fetch it to get the
+                                * buffer number
+                                */
+                               atup = heap_fetch(ad, SnapshotNow, &atup->t_ctid, &abuffer);
                                vc_setpagelock(ad, ItemPointerGetBlockNumber(&atup->t_ctid));
+                               attp = (Form_pg_attribute) GETSTRUCT(atup);
 
                                if (stats->nonnull_cnt + stats->null_cnt == 0 ||
                                        (stats->null_cnt <= 1 && stats->best_cnt == 1))
@@ -1822,7 +1830,14 @@ vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *
                                if (selratio > 1.0)
                                        selratio = 1.0;
                                attp->attdisbursion = selratio;
-                               WriteNoReleaseBuffer(ItemPointerGetBlockNumber(&atup->t_ctid));
+
+                               /*
+                                * Invalidate the cache for the tuple
+                                * and write the buffer
+                                */
+                               RelationInvalidateHeapTuple(ad, atup);
+                               WriteNoReleaseBuffer(abuffer);
+                               ReleaseBuffer(abuffer);
 
                                /* DO PG_STATISTIC INSERTS */
 
@@ -1875,10 +1890,15 @@ vc_updstats(Oid relid, int num_pages, int num_tuples, bool hasindex, VRelStats *
                heap_close(sd);
        }
 
+       /*
+        * Invalidate the cached pg_class tuple and
+        * write the buffer
+        */
        RelationInvalidateHeapTuple(rd, rtup);
 
-       /* XXX -- after write, should invalidate relcache in other backends */
-       WriteBuffer(ItemPointerGetBlockNumber(&rtup->t_ctid));
+       WriteNoReleaseBuffer(buffer);
+
+       ReleaseBuffer(buffer);
 
        heap_close(rd);
 }