Re: Really dumb planner decision

From: Matthew Wakeling
Subject: Re: Really dumb planner decision
Date: ,
Msg-id: alpine.DEB.2.00.0904161222310.4053@aragorn.flymine.org
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In response to: Re: Really dumb planner decision  (Grzegorz Jaśkiewicz)
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, Grzegorz Jaśkiewicz wrote:
> On a second look, it looks like you are are joining that view twice,
> at this point, I have no idea myself what it might be. But I guess it
> has to search over 5M rows for each of 105 in other query.
>
> I wonder what more experienced guys here will have to say about it.

That view appears as a two-column table, so I have joined something on
both of those columns, yes.

Interestingly, joining the dataset table breaks the query plan, but that
table only has 77 rows, and it is joined on by its unique primary key
index. That should be really trivial for Postgres to do.

Matthew

--
 I quite understand I'm doing algebra on the blackboard and the usual response
 is to throw objects...  If you're going to freak out... wait until party time
 and invite me along                     -- Computer Science Lecturer


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