From 22f519c92a45eb017bf2e65f36506a75309f8094 Mon Sep 17 00:00:00 2001
From: Teodor Sigaev <teodor@sigaev.ru>
Date: Thu, 17 Sep 2015 14:22:37 +0300
Subject: [PATCH] Fix bug introduced by microvacuum for GiST
Commit 013ebc0a7b7ea9c1b1ab7a3d4dd75ea121ea8ba7 introduces microvacuum for
GiST, deletetion of tuple marked LP_DEAD uses IndexPageMultiDelete while
recovery code uses IndexPageTupleDelete in loop. This causes a difference
in offset numbers of tuples to delete. Patch introduces usage of
IndexPageMultiDelete in GiST except gistplacetopage() where only one tuple is
deleted at once. That also slightly improve performance, because
IndexPageMultiDelete is more effective.
Patch changes WAL format, so bump wal page magic.
Bug report from Jeff Janes
Diagnostic and patch by Anastasia Lubennikova and me
---
src/backend/access/gist/gist.c | 5 +++++
src/backend/access/gist/gistvacuum.c | 11 ++++-------
src/backend/access/gist/gistxlog.c | 4 +---
src/include/access/xlog_internal.h | 2 +-
4 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 4edc5a75f28..53bccf6d185 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -466,6 +466,11 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
*/
START_CRIT_SECTION();
+ /*
+ * While we delete only one tuple at once we could mix calls
+ * PageIndexTupleDelete() here and PageIndexMultiDelete() in
+ * gistRedoPageUpdateRecord()
+ */
if (OffsetNumberIsValid(oldoffnum))
PageIndexTupleDelete(page, oldoffnum);
gistfillbuffer(page, itup, ntup, InvalidOffsetNumber);
diff --git a/src/backend/access/gist/gistvacuum.c b/src/backend/access/gist/gistvacuum.c
index 2337dbd7f9d..a0b0eebed3d 100644
--- a/src/backend/access/gist/gistvacuum.c
+++ b/src/backend/access/gist/gistvacuum.c
@@ -208,23 +208,20 @@ gistbulkdelete(PG_FUNCTION_ARGS)
idxtuple = (IndexTuple) PageGetItem(page, iid);
if (callback(&(idxtuple->t_tid), callback_state))
- {
- todelete[ntodelete] = i - ntodelete;
- ntodelete++;
- stats->tuples_removed += 1;
- }
+ todelete[ntodelete++] = i;
else
stats->num_index_tuples += 1;
}
+ stats->tuples_removed += ntodelete;
+
if (ntodelete)
{
START_CRIT_SECTION();
MarkBufferDirty(buffer);
- for (i = 0; i < ntodelete; i++)
- PageIndexTupleDelete(page, todelete[i]);
+ PageIndexMultiDelete(page, todelete, ntodelete);
GistMarkTuplesDeleted(page);
if (RelationNeedsWAL(rel))
diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c
index fbdbb3c51f2..c63cc8190c4 100644
--- a/src/backend/access/gist/gistxlog.c
+++ b/src/backend/access/gist/gistxlog.c
@@ -83,13 +83,11 @@ gistRedoPageUpdateRecord(XLogReaderState *record)
/* Delete old tuples */
if (xldata->ntodelete > 0)
{
- int i;
OffsetNumber *todelete = (OffsetNumber *) data;
data += sizeof(OffsetNumber) * xldata->ntodelete;
- for (i = 0; i < xldata->ntodelete; i++)
- PageIndexTupleDelete(page, todelete[i]);
+ PageIndexMultiDelete(page, todelete, xldata->ntodelete);
if (GistPageIsLeaf(page))
GistMarkTuplesDeleted(page);
}
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index 5ebaa5f69c6..590bf1729ae 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -31,7 +31,7 @@
/*
* Each page of XLOG file has a header like this:
*/
-#define XLOG_PAGE_MAGIC 0xD085 /* can be used as WAL version indicator */
+#define XLOG_PAGE_MAGIC 0xD086 /* can be used as WAL version indicator */
typedef struct XLogPageHeaderData
{
--
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