From c2a6724823c14fd442c5441eb169b2581781fef0 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Wed, 26 Mar 2014 18:04:57 +0200
Subject: [PATCH] Pass more than the first XLogRecData entry to rm_desc, with
WAL_DEBUG.
If you compile with WAL_DEBUG and enable it with wal_debug=on, we used to
only pass the first XLogRecData entry to the rm_desc routine. I think the
original assumprion was that the first XLogRecData entry contains all the
necessary information for the rm_desc routine, but that's a pretty shaky
assumption. At least standby_redo didn't get the memo.
To fix, piece together all the data in a temporary buffer, and pass that to
the rm_desc routine.
It's been like this forever, but the patch didn't apply cleanly to
back-branches. Probably wouldn't be hard to fix the conflicts, but it's
not worth the trouble.
---
src/backend/access/transam/xlog.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index b573185122f..f9d6609d44f 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1262,8 +1262,23 @@ begin:;
xlog_outrec(&buf, rechdr);
if (rdata->data != NULL)
{
+ StringInfoData recordbuf;
+
+ /*
+ * We have to piece together the WAL record data from the
+ * XLogRecData entries, so that we can pass it to the rm_desc
+ * function as one contiguous chunk. (but we can leave out any
+ * extra entries we created for backup blocks)
+ */
+ rdt_lastnormal->next = NULL;
+
+ initStringInfo(&recordbuf);
+ for (;rdata != NULL; rdata = rdata->next)
+ appendBinaryStringInfo(&recordbuf, rdata->data, rdata->len);
+
appendStringInfoString(&buf, " - ");
- RmgrTable[rechdr->xl_rmid].rm_desc(&buf, rechdr->xl_info, rdata->data);
+ RmgrTable[rechdr->xl_rmid].rm_desc(&buf, rechdr->xl_info, recordbuf.data);
+ pfree(recordbuf.data);
}
elog(LOG, "%s", buf.data);
pfree(buf.data);
--
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