From: | Dmitry Tkach <dmitry(at)openratings(dot)com> |
---|---|
To: | Dan Langille <dan(at)langille(dot)org> |
Subject: | Re: DELETE FROM t WHERE EXISTS |
Date: | 2003-02-28 22:47:04 |
Message-ID: | 3E5FE6E8.9020200@openratings.com |
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Thread: | |
Lists: | pgsql-sql |
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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