Re: Ok, why isn't it using *this* index?

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';
>
> Some other interesting things are that it uses the index on state even if
> I say "where state in ('ON','QC','BC','AB')", and it uses the index on
> state but not the one on country if I combine "where state = 'ON' and
> country = 'CANADA'".

Maybe it's just my Oracle side, but doesn't country has a too low
selectivity?

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