Re: performance with query

От: Alberto Dalmaso
Тема: Re: performance with query
Дата: ,
Msg-id: 1245251481.5027.142.camel@dalmaso-opensuse.cl
(см: обсуждение, исходный текст)
Ответ на: Re: performance with query  ("Kevin Grittner")
Ответы: Re: performance with query  ("Kevin Grittner")
Список: pgsql-performance

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performance with query  (Alberto Dalmaso, )
 Re: performance with query  (Joshua Tolley, )
 Re: performance with query  ("Kevin Grittner", )
 Re: performance with query  (Alberto Dalmaso, )
  Re: performance with query  (Matthew Wakeling, )
   Re: performance with query  (Alberto Dalmaso, )
    Re: performance with query  (Tom Lane, )
     Re: performance with query  (Alberto Dalmaso, )
      Re: performance with query  (Tom Lane, )
      Re: performance with query (OT)  ("Albe Laurenz", )
    Re: performance with query  ("Kevin Grittner", )
  Re: performance with query  ("Kevin Grittner", )
   Re: performance with query  (Alberto Dalmaso, )
    Re: performance with query  ("Kevin Grittner", )
    Re: performance with query  ("Kevin Grittner", )
     Re: performance with query  (Alberto Dalmaso, )
      Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  (Anthony Presley, )
        Re: Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  ("Albe Laurenz", )
        Re: Speeding up a query.  (Grzegorz Jaśkiewicz, )
       Re: Speeding up a query.  (Alberto Dalmaso, )
        Re: Speeding up a query.  ("Kevin Grittner", )
        Re: Speeding up a query.  (Tom Lane, )
       Re: Speeding up a query.  (Merlin Moncure, )
        Re: Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  ("Hartman, Matthew", )
       Re: Speeding up a query.  (Simon Riggs, )
        Re: Speeding up a query.  ("Hartman, Matthew", )
 Re: performance with query  (Alberto Dalmaso, )
 Re: performance with query  (Alberto Dalmaso, )
  Re: performance with query  ("Kevin Grittner", )
   Re: performance with query  (Alberto Dalmaso, )
    Re: performance with query  ("Kevin Grittner", )
     Re: performance with query  (Alberto Dalmaso, )
      Re: performance with query  ("Kevin Grittner", )
       Re: performance with query  (Tom Lane, )
        Re: performance with query  ("Kevin Grittner", )

That what i send is the quick execution, with other parameters this
query simply doesn't come to an end.
It is the little query that changing the settings (using the default
with all the query analyzer on) becames really quick, while with this
settings (with some analyzer switched off) became very slow.

I don't belleve: using this settings

set enable_hashjoin = 'on';
set enable_nestloop = 'on';
set enable_seqscan = 'on';
set enable_sort = 'on';


set from_collapse_limit = 8;
set join_collapse_limit = 3;


select * from v_fsa_2007_estrazione;
finnally end in acceptable time (156 sec)
what does it mean using join_collapse_limit = 3 (that is really a lot of
object less that what i'm using in taht query).

I'm executing an explain analyze in this new situation...
It is possible that such a configuration can create performance problem
on other queryes? (join_collapse_limit is set to a really low value)

I'll made some test in this direction.



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