[pgpool-general: 6043] Re: Question about extra queries created by pgpool master_slave_mode

Tatsuo Ishii ishii at sraoss.co.jp
Fri Apr 13 14:11:52 JST 2018

> Ooops. I see.
> I was creating new psql instance to send a SELECT query so that I saw so
> much extra queries.

Even in this case, if the new psql instance is lucky enough to connect
to a pgpool process which alreay has the cache entry, no extra query
will be issued. If there's many clients like in web application
server, eventually this will happen anyway. You can see the effect by
using pgbench. For example,

pgbench -C -c 10...

This will create 10 concurrent sessions to pgpool and for each
transaction pgbench repeats connect/disconnect. If you run pgbench
long enough, you can observe that extra queries will not be issued.

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

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