From: Tomas Vondra <tv@fuzzy.cz>
To: pgsql-performance@postgresql.org
Subject: Re: poor pefrormance with regexp searches on large tables
Date: Wed, 10 Aug 2011 19:15:44 +0200
Message-ID: <4E42BCC0.3010007@fuzzy.cz> (raw)
In-Reply-To: <CAF=aNMGRCcO+Cu3PSPL=m_OOSKOhZ+-O0uht=LQDes=7y=VfBw@mail.gmail.com>
References: <CAF=aNMHHzBKE8_P0LykDb8Bvk7eHKdytcZ9xAkz=gtpeTj87+w@mail.gmail.com>
<4E425D2D020000250003FD32@gw.wicourts.gov>
<CAF=aNMGRCcO+Cu3PSPL=m_OOSKOhZ+-O0uht=LQDes=7y=VfBw@mail.gmail.com>
Dne 10.8.2011 19:01, Grzegorz Blinowski napsal(a):
> However, changing shared_mem didn't help. We also checked system I/O
> stats during the query - and in fact there is almost no IO (even with
> suboptimal shared_memory). So the problem is not disk transfer/access
> but rather the way Postgres handles regexp queries... As I have wirtten
> it is difficult to rewrite the query syntax (the SQL generation in this
> app is quite complex), but it should be relatively easy to at least join
> all OR clauses into one regexp, I can try this from the psql CLI. I will
> post an update if anything interesting happens...
Can you post EXPLAIN ANALYZE, prefferably using explain.depesz.com?
Tomas
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To: pgsql-performance@postgresql.org
Cc: tv@fuzzy.cz
Subject: Re: poor pefrormance with regexp searches on large tables
In-Reply-To: <4E42BCC0.3010007@fuzzy.cz>
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