[pgpool-general: 1448] Re: Performance SELECT
ishii at postgresql.org
Fri Mar 1 09:01:49 JST 2013
I assume you want to retrieve large set of query results. Pgpool
needs to receive result packets from PostgreSQL then forward to
clients. We cannot lower the time for pgpool processing this in the
user land but it maybe possible to lower in kernel network stack or
You could build a test environment to comapre the current environment.
i.e. install pgpool and PostgreSQL on the same Linux machine(make sure
that backend_hostname? to ''. this forces to use UNIX domain socket,
which is much faster than TCP/IP). I think you don't need to install
PostgreSQL standbys just to profile performance).
SRA OSS, Inc. Japan
> My bottle neck is about the " Large queries", the queries with more
> 100.000 records table. The time of decadence is enormous.
> For a 1104 records result 8 seconds in direct connection and 1 minute 5 s
> in pgpool streaming mode.
> 2013/2/26 Tatsuo Ishii <ishii at postgresql.org>
>> You could always use standard performance tools such as sysstat,
>> vmstat etc. to know which is the bottle neck.
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese: http://www.sraoss.co.jp
>> > Instead when i execute simultaneous async queries (select) with AJAX, i
>> > notice my server use a lot of processes. These processes use resources.
>> > only the hardware and the net its bottleneck ?
>> > thk a lot
>> > Franz
>> > 2013/2/26 Tatsuo Ishii <ishii at postgresql.org>
>> >> > Is there a guide about performance setting by hardware ? I have an
>> >> > decrement in my select queries. I used streaming replication on two
>> >> windows
>> >> > server with PG 8.3. Sorry but client's requisites do not permit to
>> >> migrate
>> >> > to Linux. :-(
>> >> There's no performance documentation yet. However I think the major
>> >> bottle neck is network, including netowrk hardware and TCP/IP stack.
>> >> Also too trivial SELECT (like pgbench -S) will mask the effect of
>> >> pgpool performance boosting in load balancing.
>> >> --
>> >> Tatsuo Ishii
>> >> SRA OSS, Inc. Japan
>> >> English: http://www.sraoss.co.jp/index_en.php
>> >> Japanese: http://www.sraoss.co.jp
>> > --
>> > *Franci anni'80*
>> > ♫
>> > (\ /)
>> > ( . .) ♥●•٠·˙
>> > c(")(")
> *Franci anni'80*
> (\ /)
> ( . .) ♥●•٠·˙
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