Re: Surprise :-(
От | Steve Wolfe |
---|---|
Тема | Re: Surprise :-( |
Дата | |
Msg-id | 001801c255d3$7aecb9b0$d281f6cc@WEASEL обсуждение исходный текст |
Ответ на | Re: Surprise :-( ("Mihai Gheorghiu" <tanethq@earthlink.net>) |
Список | pgsql-general |
I've ran into similar oddnesses twice in the past two months. In both cases, a developper came to me and said that a particular query ran very quickly the day the table was created and populated, and ran very slowly starting the next day, after the DB had been VACUUM'ed. In both cases, their WHERE clause used operations such as concatenations on fields that did not have indexes. In both cases, creating the indexes speeded up the query, dropping the cost from some obscene number to a very low one. ( on the order of 8000 to 60). I'm not sure why the queries worked well before the database was VACUUM'ed, but it's happened to me twice now - and it sounds similar enough to your situation that you may want to look at whether you have appropriate indexes created on your table. steve
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