[pgpool-general: 4620] Re: Long running temp table checks

Tatsuo Ishii ishii at postgresql.org
Wed Apr 6 00:00:27 JST 2016

> I've noticed strange long running queries on our PostgreSQL (9.4.4) running
> with  PgPool-II (3.4.3). Quite frequently there are queries like
> SELECT count(*) FROM pg_class AS c, pg_namespace AS n WHERE c.relname =
> <tablename> AND c.relnamespace = n.oid AND n.nspname ~ '^pg_temp_'
> in the pg_stat_activity view. I assume, these are PgPool-II checks to
> identify temp tables on the master (which can be enabled/disabled by
> check_temp_table config switch). The strange thing about it is, that
> sometimes the query hangs in the view (in 'active' state) well over 10
> minutes, without being held by lock or whatever.
> I've checked the running postgres process with strace and it is in the
> recvfrom() on the socket with the PgPool-II connection.
> Running the query localy takes milliseconds (as expected).
> Have anyone encountered such behaviour, or is it to be expected and I'm
> misunderstanding something?

Probably it's a false alarm. See the FAQ for more details.


Best regards,
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php

More information about the pgpool-general mailing list