Re: Different query plans on same servers

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Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
 
> I'd wonder first if you have the same statistics settings on both.
> The big problem here is that the estimation of the join size is
> bad (8588 versus 0).
 
But both servers develop that estimate for the join size.  I was
wondering more about whether the costing factors were really the
same:
 
slow:
 
   ->  Nested Loop
          (cost=0.00..792824.51 rows=8588 width=275)
          (actual time=3269.997..3269.997 rows=0 loops=1)
 
versus fast:
 
         ->  Hash Join
                (cost=857.00..31152.80 rows=8588 width=275)
                (actual time=37.968..37.968 rows=0 loops=1)
 
The hash join path must look more expensive on the first machine,
for some reason.
 
Mario, could you post the result of running this query from both
servers?:
 
http://wiki.postgresql.org/wiki/Server_Configuration
 
-Kevin

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