Re: setting for maximum acceptable plan cost? - Mailing list pgsql-general

From Joshua D. Drake
Subject Re: setting for maximum acceptable plan cost?
Date
Msg-id 20071102144500.5f543602@scratch
Whole thread Raw
In response to setting for maximum acceptable plan cost?  ("Jeffrey W. Baker" <jwbaker@acm.org>)
Responses Re: setting for maximum acceptable plan cost?  ("Jeffrey W. Baker" <jwbaker@acm.org>)
List pgsql-general
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On Fri, 02 Nov 2007 13:49:27 -0700
"Jeffrey W. Baker" <jwbaker@acm.org> wrote:

> Nested Loop Left Join  (cost=13920.16..2257575559347.46
> rows=3691992705807 width=128)
> 
> After a call to ANALYZE, the same query gave me:
> 
> Merge Left Join  (cost=16382.02..16853.87 rows=126768 width=59)
> 
> And runs in 5 seconds.  If I had been able to tell pg to reject any
> plan with cost over, say 10E9, that would have saved my server from
> half an hour of nested sequential scans.

I am confused as to why you would want to do that... seems like a
band aid for lack of maintenance.

> 
> Should I just use statement_timeout as a proxy for this?
> 

That would yes but see my point about maintenance above.

Joshua D. Drake



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