BTW while going about testing this, I noticed that we forbid
pg_walfile_name() while in recovery. That restriction was added by
commit 370f770c15a4 because ThisTimeLineID was not set correctly during
recovery. That was supposed to be fixed by commit 1148e22a82ed, so I
thought that it should be possible to remove the restriction. However,
I did that per the attached patch, but was quickly disappointed because
ThisTimeLineID seems to remain zero in a standby for reasons that I
didn't investigate.
--
Álvaro Herrera 39°49'30"S 73°17'W — https://www.EnterpriseDB.com/
"The problem with the facetime model is not just that it's demoralizing, but
that the people pretending to work interrupt the ones actually working."
(Paul Graham)
>From 1b57e504b9a7eeddf2d99e615f21c5aec042a908 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Wed, 25 Aug 2021 19:55:43 -0400
Subject: [PATCH] Don't forbid pg_walfile_name in recovery mode
---
src/backend/access/transam/xlogfuncs.c | 7 -------
1 file changed, 7 deletions(-)
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index b98deb72ec..99b22d0b30 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -503,13 +503,6 @@ pg_walfile_name(PG_FUNCTION_ARGS)
XLogRecPtr locationpoint = PG_GETARG_LSN(0);
char xlogfilename[MAXFNAMELEN];
- if (RecoveryInProgress())
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("recovery is in progress"),
- errhint("%s cannot be executed during recovery.",
- "pg_walfile_name()")));
-
XLByteToPrevSeg(locationpoint, xlogsegno, wal_segment_size);
XLogFileName(xlogfilename, ThisTimeLineID, xlogsegno, wal_segment_size);
--
2.30.2
