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Re: Really dumb planner decision

From: Matthew Wakeling
Subject: Re: Really dumb planner decision
Date: ,
Msg-id: alpine.DEB.2.00.0904161651420.4053@aragorn.flymine.org
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In response to: Re: Really dumb planner decision  (Robert Haas)
Responses: Re: Really dumb planner decision  (Tom Lane)
List: pgsql-performance

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Really dumb planner decision  (Matthew Wakeling, )
 Re: Really dumb planner decision  (Grzegorz Jaśkiewicz, )
  Re: Really dumb planner decision  (Matthew Wakeling, )
   Re: Really dumb planner decision  (Robert Haas, )
    Re: Really dumb planner decision  (Matthew Wakeling, )
     Re: Really dumb planner decision  (Merlin Moncure, )
      Re: Really dumb planner decision  (Tom Lane, )
       Re: Really dumb planner decision  ("Kevin Grittner", )
        Re: Really dumb planner decision  (Merlin Moncure, )
       Re: Really dumb planner decision  (Robert Haas, )
        Re: Really dumb planner decision  (Matthew Wakeling, )
         Re: Really dumb planner decision  (Tom Lane, )
 Re: Really dumb planner decision  (Grzegorz Jaśkiewicz, )
  Re: Really dumb planner decision  (Matthew Wakeling, ) 
On Thu, 16 Apr 2009, Robert Haas wrote:
> I hasten to point out that I only suggested raising them to the moon
> as a DEBUGGING strategy, not a production configuration.

The problem is that we have created a view that by itself a very
time-consuming query to answer, relying on it being incorporated into a
query that will constrain it and cause it to be evaluated a lot quicker.
This kind of scenario kind of guarantees a bad plan as soon as the number
of tables reaches from_collapse_limit.

Matthew

--
 Failure is not an option. It comes bundled with your Microsoft product.
                                                 -- Ferenc Mantfeld

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