Re: Ok, why isn't it using *this* index?
От | Paul Tomblin |
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Тема | Re: Ok, why isn't it using *this* index? |
Дата | |
Msg-id | 20010401161029.B26334@allhats.xcski.com обсуждение исходный текст |
Ответ на | Re: Ok, why isn't it using *this* index? ("ADBAAMD" <adba.amdocs@bell.ca>) |
Список | pgsql-general |
Quoting ADBAAMD (adba.amdocs@bell.ca): > Paul Tomblin wrote: > > I have a table with columns 'country' and 'state'. I put indexes on both > > of them. I've done the "vacuum analyze" as per the faq. But when I ask > > it to explain, it says it will use the index on 'state' if I do a > > select * from waypoint where state = 'ON'; > > but it won't use the index on 'country' if I do a > > select * from waypoint where country = 'CANADA'; > > Maybe it's just my Oracle side, but doesn't country has a too low > selectivity? If I try explain select * from waypoint where country = 'BELIZE'; a query that will only select one record out of the 8300-odd, it still doesn't use the index. Seq Scan on waypoint (cost=455.13 rows=6813 width=130) -- Paul Tomblin <ptomblin@xcski.com>, not speaking for anybody Mommy, what does "Formatting Drive C:" mean?
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