Re: rewrite in to exists?
От | LN Cisneros |
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Тема | Re: rewrite in to exists? |
Дата | |
Msg-id | 24864010.1063897195181.JavaMail.root@statler.psp.pas.earthlink.net обсуждение исходный текст |
Ответ на | rewrite in to exists? (LN Cisneros <lnsea@earthlink.net>) |
Ответы |
Re: rewrite in to exists?
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Список | pgsql-performance |
On Thu, 18 Sep 2003 13:23:37 +0800, "Christopher Kings-Lynne" <snip> >To the original poster: You did not provide a lot of information, but >the following suggestions might give you an idea ... <snip> > Yes, sorry about that. But in my query for a set of dates returned from the subquery I would then like to get all recordsthat match this set of dates (ordered). I believe this query will work and hopefully speed it up (the "IN" query is extremely slow)...I give this one a try: >SELECT t1.code, t1.id, t1.date_of_service > FROM tbl t1 INNER JOIN > (SELECT DISTINCT date_of_service > FROM tbl > WHERE xxx >= '29800' AND xxx <= '29909' > AND code = 'XX' > ) AS t2 ON (t1.date_of_service = t2.date_of_service) > WHERE t1.client_code = 'XX' > ORDER BY id, date_of_service; A question I have is is the "DISTINCT" really going to help or is it just going to throw another sort into the mix makingit slower? Thanks for the help! Laurette
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