From: Dmitry Tkach <dmitry@openratings.com>
To: Dan Langille <dan@langille.org>
Subject: Re: DELETE FROM t WHERE EXISTS
Date: Fri, 28 Feb 2003 17:47:04 -0500
Message-ID: <3E5FE6E8.9020200@openratings.com> (raw)
In-Reply-To: <3E5F530B.1649.424D34C1@localhost>
References: <3E5F530B.1649.424D34C1@localhost>
What about
select * into temp rows_to_keep from clp order by commit_date limit 100;
truncate clp;
insert into clp select * from rows_to_keep;
Dima.
Dan Langille wrote:
> Hi folks,
>
> I wanted to delete "old" rows from a table. These are the rows I
> want to keep:
>
> SELECT *
> FROM clp
> ORDER BY commit_date
> LIMIT 100
>
> So I tried this:
>
> DELETE FROM clp
> WHERE NOT EXISTS (
> SELECT *
> FROM clp
> ORDER BY commit_date
> LIMIT 100);
>
> Uhh uhh, nothing deleted. I don't understand why.
>
> OK, I can do this instead:
>
> DELETE from clp
> where commit_log_id NOT in (
> SELECT commit_log_id
> FROM clp
> ORDER BY commit_date
> LIMIT 100);
>
> Can you think of a better way?
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To: pgsql-sql@postgresql.org
Cc: dmitry@openratings.com, dan@langille.org
Subject: Re: DELETE FROM t WHERE EXISTS
In-Reply-To: <3E5FE6E8.9020200@openratings.com>
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