From f918b5d219b7200d204515b32346183b97d031ae Mon Sep 17 00:00:00 2001 From: Amit Kapila Date: Fri, 8 May 2020 08:56:03 +0530 Subject: [PATCH] Fix inconsistency in pg_buffercache docs. Commit 6e654546fb avoids locking bufmgr partitions to make pg_buffercache less disruptive on production systems but forgot to update the docs. Reported-by: Sawada Masahiko Author: Sawada Masahiko Reviewed-by: Amit Kapila Backpatch-through: 10 Discussion: https://postgr.es/m/CA+fd4k6sD8oeP1qJbFAor=rCpYckU9DsywHiYx3x5Hz5Z8Ua_w@mail.gmail.com --- doc/src/sgml/pgbuffercache.sgml | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/pgbuffercache.sgml b/doc/src/sgml/pgbuffercache.sgml index fd2446d654..b2b5bce480 100644 --- a/doc/src/sgml/pgbuffercache.sgml +++ b/doc/src/sgml/pgbuffercache.sgml @@ -135,12 +135,11 @@ - When the pg_buffercache view is accessed, internal buffer - manager locks are taken for long enough to copy all the buffer state - data that the view will display. - This ensures that the view produces a consistent set of results, while not - blocking normal buffer activity longer than necessary. Nonetheless there - could be some impact on database performance if this view is read often. + Since buffer manager locks are not taken to copy the buffer state data that + the view will display, accessing pg_buffercache view + has less impact on normal buffer activity but it doesn't provide a consistent + set of results across all buffers. However, we ensure that the information of + each buffer is self-consistent.