Re: sunquery and estimated rows

On Sun, 2004-04-18 at 19:09, Tom Lane wrote:
> Markus Bertheau <twanger@bluetwanger.de> writes:
> >  , 17.04.2004,  01:45, Tom Lane :
> >> The planner sees that as "where scope = <some complicated expression>"
> >> and falls back to a default estimate.  It won't simplify a sub-select
> >> to a constant.  (Some people consider that a feature ;-).)
> 
> > Why?
> 
> It's the only way to prevent it from simplifying when you don't want it
> to.

I'm having a difficult time coming up with a circumstance where that is
beneficial except when stats are out of whack.

Doesn't a prepared statement also falls back to the default estimate for
variables.

-- 
Rod Taylor <rbt [at] rbt [dot] ca>

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