Re: Help speeding up delete

[Scott Lamb <slamb@xxxxxxxxx>]

On Nov 14, 2005, at 2:07 PM, Steve Wampler wrote:
> # SELECT at.id FROM "tmp_table2" at, "tmp_tabl2e" a
> #   WHERE at.id=a.id and a.name='obsid' and a.value='oid080505';

Isn't this equivalent?

select id from tmp_table2 where name = 'obsid' and value = 'oid080505';

> # DELETE FROM "tmp_table2" WHERE id IN
> # (SELECT at.id FROM "tmp_table2" at, "tmp_table2" a
> #   WHERE at.id=a.id and a.name='obsid' and a.value='oid080505');

and this?

delete from tmp_table2 where name = 'obsid' and value = 'oid080505';

Why are you doing a self-join using id, which I assume is a primary key?

--
Scott Lamb <http://www.slamb.org/>



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