From 95563e7bbf597bb69a273d7cfbe664f1796391b6 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 19 Sep 2000 19:30:03 +0000
Subject: [PATCH] Make sure that FlushRelationBuffers() is invoked by all paths
through vacuum.c. This is needed to make the world safe for pg_upgrade.
---
src/backend/commands/vacuum.c | 114 +++++++++++++++++++++-------------
1 file changed, 72 insertions(+), 42 deletions(-)
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 7d4005d21d5..3bd65fed765 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.165 2000/09/12 04:49:07 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.166 2000/09/19 19:30:03 tgl Exp $
*
*-------------------------------------------------------------------------
@@ -397,12 +397,6 @@ vacuum_rel(Oid relid, bool analyze, bool is_toastrel)
*/
onerel = heap_open(relid, AccessExclusiveLock);
- /*
- * Remember the relations TOAST relation for later
- *
- */
- toast_relid = onerel->rd_rel->reltoastrelid;
-
#ifndef NO_SECURITY
if (!pg_ownercheck(GetUserId(), RelationGetRelationName(onerel),
RELNAME))
@@ -416,6 +410,11 @@ vacuum_rel(Oid relid, bool analyze, bool is_toastrel)
}
#endif
+ /*
+ * Remember the relation'ss TOAST relation for later
+ */
+ toast_relid = onerel->rd_rel->reltoastrelid;
+
/*
* Set up statistics-gathering machinery.
*/
@@ -430,7 +429,8 @@ vacuum_rel(Oid relid, bool analyze, bool is_toastrel)
reindex = false;
vacuum_pages.num_pages = fraged_pages.num_pages = 0;
scan_heap(vacrelstats, onerel, &vacuum_pages, &fraged_pages);
- if (IsIgnoringSystemIndexes() && IsSystemRelationName(RelationGetRelationName(onerel)))
+ if (IsIgnoringSystemIndexes() &&
+ IsSystemRelationName(RelationGetRelationName(onerel)))
reindex = true;
/* Now open indices */
@@ -459,30 +459,54 @@ vacuum_rel(Oid relid, bool analyze, bool is_toastrel)
if (vacuum_pages.num_pages > 0)
{
for (i = 0; i < nindices; i++)
- vacuum_index(&vacuum_pages, Irel[i], vacrelstats->num_tuples, 0);
+ vacuum_index(&vacuum_pages, Irel[i],
+ vacrelstats->num_tuples, 0);
}
else
- /* just scan indices to update statistic */
{
+ /* just scan indices to update statistic */
for (i = 0; i < nindices; i++)
scan_index(Irel[i], vacrelstats->num_tuples);
}
}
- if (fraged_pages.num_pages > 0) /* Try to shrink heap */
- repair_frag(vacrelstats, onerel, &vacuum_pages, &fraged_pages, nindices, Irel);
+ if (fraged_pages.num_pages > 0)
+ {
+ /* Try to shrink heap */
+ repair_frag(vacrelstats, onerel, &vacuum_pages, &fraged_pages,
+ nindices, Irel);
+ }
else
{
if (Irel != (Relation *) NULL)
close_indices(nindices, Irel);
- if (vacuum_pages.num_pages > 0) /* Clean pages from
- * vacuum_pages list */
+ if (vacuum_pages.num_pages > 0)
+ {
+ /* Clean pages from vacuum_pages list */
vacuum_heap(vacrelstats, onerel, &vacuum_pages);
+ }
+ else
+ {
+ /*
+ * Flush dirty pages out to disk. We must do this even if we
+ * didn't do anything else, because we want to ensure that all
+ * tuples have correct on-row commit status on disk (see
+ * bufmgr.c's comments for FlushRelationBuffers()).
+ */
+ i = FlushRelationBuffers(onerel, vacrelstats->num_pages);
+ if (i < 0)
+ elog(ERROR, "VACUUM (vacuum_rel): FlushRelationBuffers returned %d",
+ i);
+ }
}
if (reindex)
activate_indexes_of_a_table(relid, true);
- /* ok - free vacuum_pages list of reaped pages */
+ /*
+ * ok - free vacuum_pages list of reaped pages
+ *
+ * Isn't this a waste of code? Upcoming commit should free memory, no?
+ */
if (vacuum_pages.num_pages > 0)
{
vacpage = vacuum_pages.pagedesc;
@@ -498,12 +522,14 @@ vacuum_rel(Oid relid, bool analyze, bool is_toastrel)
/* update statistics in pg_class */
update_relstats(vacrelstats->relid, vacrelstats->num_pages,
- vacrelstats->num_tuples, vacrelstats->hasindex, vacrelstats);
+ vacrelstats->num_tuples, vacrelstats->hasindex,
+ vacrelstats);
- /* If the relation has a secondary toast one, vacuum that too
+ /*
+ * If the relation has a secondary toast one, vacuum that too
* while we still hold the lock on the master table. We don't
* need to propagate "analyze" to it, because the toaster
- * allways uses hardcoded index access and statistics are
+ * always uses hardcoded index access and statistics are
* totally unimportant for toast relations
*/
if (toast_relid != InvalidOid)
@@ -1820,12 +1846,20 @@ failed to add item with len = %u to page %u (free space %u, nusd %u, noff %u)",
pfree(Nvacpagelist.pagedesc);
}
- /* truncate relation, after flushing any dirty pages out to disk */
+ /*
+ * Flush dirty pages out to disk. We do this unconditionally, even if
+ * we don't need to truncate, because we want to ensure that all tuples
+ * have correct on-row commit status on disk (see bufmgr.c's comments
+ * for FlushRelationBuffers()).
+ */
+ i = FlushRelationBuffers(onerel, blkno);
+ if (i < 0)
+ elog(ERROR, "VACUUM (repair_frag): FlushRelationBuffers returned %d",
+ i);
+
+ /* truncate relation, if needed */
if (blkno < nblocks)
{
- i = FlushRelationBuffers(onerel, blkno);
- if (i < 0)
- elog(FATAL, "VACUUM (repair_frag): FlushRelationBuffers returned %d", i);
blkno = smgrtruncate(DEFAULT_SMGR, onerel, blkno);
Assert(blkno >= 0);
vacrelstats->num_pages = blkno; /* set new number of blocks */
@@ -1840,7 +1874,6 @@ failed to add item with len = %u to page %u (free space %u, nusd %u, noff %u)",
pfree(vacpage);
if (vacrelstats->vtlinks != NULL)
pfree(vacrelstats->vtlinks);
-
}
/*
@@ -1860,7 +1893,7 @@ vacuum_heap(VRelStats *vacrelstats, Relation onerel, VacPageList vacuum_pages)
nblocks = vacuum_pages->num_pages;
nblocks -= vacuum_pages->empty_end_pages; /* nothing to do with
- * them */
+ * them */
for (i = 0, vacpage = vacuum_pages->pagedesc; i < nblocks; i++, vacpage++)
{
@@ -1873,33 +1906,30 @@ vacuum_heap(VRelStats *vacrelstats, Relation onerel, VacPageList vacuum_pages)
}
}
+ /*
+ * Flush dirty pages out to disk. We do this unconditionally, even if
+ * we don't need to truncate, because we want to ensure that all tuples
+ * have correct on-row commit status on disk (see bufmgr.c's comments
+ * for FlushRelationBuffers()).
+ */
+ Assert(vacrelstats->num_pages >= vacuum_pages->empty_end_pages);
+ nblocks = vacrelstats->num_pages - vacuum_pages->empty_end_pages;
+
+ i = FlushRelationBuffers(onerel, nblocks);
+ if (i < 0)
+ elog(ERROR, "VACUUM (vacuum_heap): FlushRelationBuffers returned %d",
+ i);
+
/* truncate relation if there are some empty end-pages */
if (vacuum_pages->empty_end_pages > 0)
{
- Assert(vacrelstats->num_pages >= vacuum_pages->empty_end_pages);
- nblocks = vacrelstats->num_pages - vacuum_pages->empty_end_pages;
elog(MESSAGE_LEVEL, "Rel %s: Pages: %u --> %u.",
RelationGetRelationName(onerel),
vacrelstats->num_pages, nblocks);
-
- /*
- * We have to flush "empty" end-pages (if changed, but who knows
- * it) before truncation
- *
- * XXX is FlushBufferPool() still needed here?
- */
- FlushBufferPool();
-
- i = FlushRelationBuffers(onerel, nblocks);
- if (i < 0)
- elog(FATAL, "VACUUM (vacuum_heap): FlushRelationBuffers returned %d", i);
-
nblocks = smgrtruncate(DEFAULT_SMGR, onerel, nblocks);
Assert(nblocks >= 0);
- vacrelstats->num_pages = nblocks; /* set new number of
- * blocks */
+ vacrelstats->num_pages = nblocks; /* set new number of blocks */
}
-
}
/*
--
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