Re: Union strange explain - Mailing list pgsql-admin

From Gaetano Mendola
Subject Re: Union strange explain
Date
Msg-id 005001c2240d$23d176e0$070afea9@GMENDOLA2
Whole thread Raw
In response to Re: Union strange explain  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
Responses Re: Union strange explain  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
List pgsql-admin
Stephan  wrote:
> number of rows returned).  I think there was some question about
> whether it was safe to do that optimization (ie,
> is select * from (a union [all] b) where condition
> always the same as
>  select * from a where condition union [all]
>  select * from b where condition
> )

Yes but with a View the condition is always extern.
I'm understanding that I don't have any possibility to
optimize that view, I'm wrong ?


Ciao
Gaetano




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