Re: Optimizer bug??
От | Gaetano Mendola |
---|---|
Тема | Re: Optimizer bug?? |
Дата | |
Msg-id | 40B241B4.4090803@bigfoot.com обсуждение исходный текст |
Ответ на | Optimizer bug?? ("Ismail Kizir" <ikizir@tumgazeteler.com>) |
Список | pgsql-hackers |
Ismail Kizir wrote: > Hi everybody, > > 1 .... EXPLAIN SELECT COUNT(*) AS c FROM articletbl WHERE > ((mydate BETWEEN '2004-04-24' AND '2004-05-24' ) > ) > > 2 .... EXPLAIN SELECT COUNT(*) AS c FROM articletbl WHERE > ((mydate = '2004-04-24') > ) > > (I ran VACUUM ANALYZE before running those) > > mydate is an indexed date column. > The optimizer optimizes the second query but, it doesn't optimize the first > one and decides to make a "sequential scan". > Is this a bug? > Or may someone explain me the reason? give us the result of these queries: SELECT COUNT(*) FROM articletbl; SELECT COUNT(*) AS c FROM articletbl WHERE mydate BETWEEN '2004-04-24' AND '2004-05-24'; SELECT COUNT(*) AS c FROM articletbl WHERE mydate = '2004-04-24'; Regards Gaetano Mendola
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