Fix hot standby bug with GiST scans.

hlinnaka · hlinnaka · commit 601c01e08ded · 2014-04-08T14:51:49.000+03:00
Don't reset the rightlink of a page when replaying a page update record.
This was a leftover from pre-hot standby days, when it was not possible to
have scans concurrent with WAL replay. Resetting the right-link was not
necessary back then either, but it was done for the sake of tidiness. But
with hot standby, it's wrong, because a concurrent scan might still need it.

Backpatch all versions with hot standby, 9.0 and above.
diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c
@@ -182,7 +182,6 @@ gistRedoPageUpdateRecord(XLogRecPtr lsn, XLogRecord *record)
 		GistPageSetLeaf(page);
 	}
 
-	GistPageGetOpaque(page)->rightlink = InvalidBlockNumber;
 	PageSetLSN(page, lsn);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);

Original file line number	Diff line number	Diff line change
`@@ -182,7 +182,6 @@ gistRedoPageUpdateRecord(XLogRecPtr lsn, XLogRecord *record)`
`182`	`182`	`GistPageSetLeaf(page);`
`183`	`183`	`}`
`184`	`184`
`185`		`- GistPageGetOpaque(page)->rightlink = InvalidBlockNumber;`
`186`	`185`	`PageSetLSN(page, lsn);`
`187`	`186`	`MarkBufferDirty(buffer);`
`188`	`187`	`UnlockReleaseBuffer(buffer);`