Re: [SQL] More efficient DELETE ... ? - Mailing list pgsql-sql

The Hermit Hacker <scrappy@hub.org> writes:
> This looks painful ...

> DELETE FROM webhit_referer_raw
>       WHERE oid IN ( SELECT w.oid
>                        FROM webhit_referer_raw w, referrer_data r
>                       WHERE stat_date < 'Jan 17 2000 15:05:00'
>                         AND w.referrer_url = r.referrer );

I believe you can do

DELETE FROM webhit_referer_raw
WHERE referrer_url = referrer_data.referrer     AND referrer_data.stat_date < 'Jan 17 2000 15:05:00';

(I assume stat_date is in referrer_data, otherwise this'd be easy.)

This is an example where Postgres' willingness to create implicit FROM
clause entries is a win ... AFAIK you couldn't do it in standard SQL,
since for some reason DELETE doesn't take a FROM clause.
        regards, tom lane