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Re: PG using index+filter instead only use index - Mailing list pgsql-performance

From Tom Lane
Subject Re: PG using index+filter instead only use index
Date
Msg-id 5135.1269028162@sss.pgh.pa.us
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In response to PG using index+filter instead only use index  (Alexandre de Arruda Paes <adaldeia@gmail.com>)
Responses Re: PG using index+filter instead only use index
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Alexandre de Arruda Paes <adaldeia@gmail.com> writes:
> My question: if the cost is exactly the same, why PG choose the index
> ict13t2 on ct13t and apply a filter instead use the primary key ?

Why shouldn't it, if the estimated costs are the same?  You didn't
actually demonstrate they're the same though.

The cost estimates look a bit unusual to me; are you using nondefault
cost parameters, and if so what are they?

            regards, tom lane

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