From ea42cc18c35381f639d45628d792e790ff39e271 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 23 Mar 2017 14:08:23 -0400 Subject: Track the oldest XID that can be safely looked up in CLOG. This provides infrastructure for looking up arbitrary, user-supplied XIDs without a risk of scary-looking failures from within the clog module. Normally, the oldest XID that can be safely looked up in CLOG is the same as the oldest XID that can reused without causing wraparound, and the latter is already tracked. However, while truncation is in progress, the values are different, so we must keep track of them separately. Craig Ringer, reviewed by Simon Riggs and by me. Discussion: http://postgr.es/m/CAMsr+YHQiWNEi0daCTboS40T+V5s_+dst3PYv_8v2wNVH+Xx4g@mail.gmail.com --- doc/src/sgml/monitoring.sgml | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'doc/src') diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 356a2f0c4c4..e930731b162 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1017,6 +1017,10 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser OldSnapshotTimeMapLock Waiting to read or update old snapshot control information. + + CLogTruncationLock + Waiting to truncate the transaction log or waiting for transaction log truncation to finish. + clog Waiting for I/O on a clog (transaction status) buffer. -- cgit v1.2.3