From: Alvaro Herrera <alvherre@commandprompt.com>
To: Daniel Cristian Cruz <danielcristian@gmail.com>
Cc: pgsql-admin <pgsql-admin@postgresql.org>
Subject: Re: Not so simple query and a half million loop
Date: Tue, 2 Dec 2008 13:07:37 -0300
Message-ID: <20081202160737.GJ5672@alvh.no-ip.org> (raw)
In-Reply-To: <48d0cacb0812020210s22d44b84nc0a6719c97502e87@mail.gmail.com>
References: <48d0cacb0812010526i7c51b29fs9319618b3aaf3f49@mail.gmail.com>
<48d0cacb0812010721t783bdcd9g36090504b7070a06@mail.gmail.com>
<48d0cacb0812020210s22d44b84nc0a6719c97502e87@mail.gmail.com>
Daniel Cristian Cruz escribió:
> No one knows why I got "actual time=0.014..0.570 rows=30 loops=511222"
> and "actual time=0.005..0.006 rows=1 loops=15158976"?
>
> With:
> cu.cal_user_type = 'u' AND
> cu.cal_recur_date = COALESCE((SELECT cd.cal_start FROM egw_cal_dates
> icd WHERE icd.cal_id = cd.cal_id AND icd.cal_start = cd.cal_start AND
> icd.cal_start <> 0), 0)
> ~ 450 seconds
I don't know, but why are you using such an expression instead of an
outer join?
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
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To: pgsql-performance@postgresql.org
Cc: alvherre@commandprompt.com, danielcristian@gmail.com, pgsql-admin@postgresql.org
Subject: Re: Not so simple query and a half million loop
In-Reply-To: <20081202160737.GJ5672@alvh.no-ip.org>
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