Re: Regexps - never completing join.
От | Scott Marlowe |
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Тема | Re: Regexps - never completing join. |
Дата | |
Msg-id | dcc563d10805161335m73a938e0t4b1a6578b2d19999@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Regexps - never completing join. (Rusty Conover <rconover@infogears.com>) |
Ответы |
Re: Regexps - never completing join.
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Список | pgsql-performance |
On Wed, May 14, 2008 at 9:33 AM, Rusty Conover <rconover@infogears.com> wrote: > Returning to this problem this morning, I made some more insight. > > One way I did find that worked to control the loop (but doesn't yield the > same results because its a left join) > > select wc_rule.id from wc_rule left join classifications on > classifications.classification ~* wc_rule.regexp; If you do that and exclude the extra rows added to the right with somthing like and wc_rule.somefield IS NOT NULL does it run fast and give you the same answers as the regular join? I'm guessing that this could be optimized to use a hash agg method of joining for text, but I'm no expert on the subject.
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