From: Bruno Wolff III <bruno@wolff.to>
To: pginfo <pginfo@t1.unisoftbg.com>
Cc: pgsql-sql@postgresql.org <pgsql-sql@postgresql.org>
Subject: Re: update and IN vs. EXISTS
Date: Sat, 1 Feb 2003 08:54:12 -0600
Message-ID: <20030201145412.GA29037@wolff.to> (raw)
In-Reply-To: <3E3BB210.5C51478C@t1.unisoftbg.com>
References: <3E3BB210.5C51478C@t1.unisoftbg.com>
On Sat, Feb 01, 2003 at 12:40:00 +0100,
pginfo <pginfo@t1.unisoftbg.com> wrote:
>
> If I try to execute:
> update Table1 set fieldForUpdate = 1 where ID IN (select T2.ID from
> Table2);
> it is running very slow.
You might try:
update Table1 set fieldForUpdate = 1 from Table2 where Table1.id = Table2.id;
This uses a nonstandard postgres extension and may not be portable, if that
is a concern.
INs are being speeded up in 7.4, so the original form might work a lot better
in the next release.
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To: pgsql-sql@postgresql.org
Cc: bruno@wolff.to, pginfo@t1.unisoftbg.com
Subject: Re: update and IN vs. EXISTS
In-Reply-To: <20030201145412.GA29037@wolff.to>
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