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authorAmit Kapila <akapila@postgresql.org>2020-05-08 08:33:05 +0530
committerAmit Kapila <akapila@postgresql.org>2020-05-08 08:33:05 +0530
commitf9463d2a903da930531d124ea8bbbff8c097d86b (patch)
tree00a79698b8443bc231495a78b721b2dc2f3dc434
parentf2ff2035962cd2ddd56c1593709d48ca0d3a78c5 (diff)
downloadpostgresql-f9463d2a903da930531d124ea8bbbff8c097d86b.tar.gz
postgresql-f9463d2a903da930531d124ea8bbbff8c097d86b.zip
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
-rw-r--r--doc/src/sgml/pgbuffercache.sgml11
1 files changed, 5 insertions, 6 deletions
diff --git a/doc/src/sgml/pgbuffercache.sgml b/doc/src/sgml/pgbuffercache.sgml
index fd2446d6542..b2b5bce480c 100644
--- a/doc/src/sgml/pgbuffercache.sgml
+++ b/doc/src/sgml/pgbuffercache.sgml
@@ -135,12 +135,11 @@
</para>
<para>
- When the <structname>pg_buffercache</structname> 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 <structname>pg_buffercache</structname> 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.
</para>
</sect2>