Re: again, LIKE operator
От | Andy Samuel |
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Тема | Re: again, LIKE operator |
Дата | |
Msg-id | 000d01c19b55$82c37ea0$0200a8c0@edpgm обсуждение исходный текст |
Ответ на | again, LIKE operator ("Andy Samuel" <andysamuel@geocities.com>) |
Ответы |
Re: again, LIKE operator
|
Список | pgsql-general |
Just forget my previous email.
PostgreSQL does not use index on LIKE 'a%' but it will use the index if LIKE 'ab%' or something longer.
So the optimizer thinks it is not good enough if it's only 1 character.
Well done !
Thank you
Andy
----- Original Message -----From: Andy SamuelSent: Saturday, January 12, 2002 11:35 AMSubject: [GENERAL] again, LIKE operatorDear AllI've search the archive and manuals and it says I should use C locale in order to enable LIKE to use index.Postgresql was installed after I set the locale to C. So I'm sure the initdb will use C.From EXPLAIN I know that :SELECT * FROM GuestProfile WHERE FirstName LIKE 'a' will use index on FirstNamebutSELECT * FROM GuestProfile WHERE FirstName LIKE 'a%' will not use Index on FirstNameI have 9,999,999 records and it was VACUUM ANALYZE-d.How do I enforce the optimizer to use the index ?Thank you in advanceAndy
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