Re: Multiple column index usage question

That's interesting.  So if you have a composite index on two columns, is
there much of a reason (usually) to create single indexes on each of the
two columns?  I guess the single indexes might be slightly faster
depending on the number of different values/combinations, so probably
"it depends" eh?


On Fri, 19 Jan 2007 16:57:42 -0600, "Ron Johnson"
<ron.l.johnson@cox.net> said:
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> On 01/19/07 15:53, Jan Muszynski wrote:
> > Rather simple question, of which I'm not sure of the answer.
> >
> > If I have a multiple column index, say:
> >     Index index1 on tableA (foo,bar)
> >
> > and I then:
> >     Select * from "tableA" where foo = <some value>
> >
> > Will index1 be used, or am I looking at a seqscan in all circumstances?
>
> Yes, it will use the index.
>
> However, in earlier versions, the lvalue & rvalue needed to match in
> type to use the index.
>
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