Re: [SQL] EXTERNAL storage and substring on long strings

От: Scott Cain
Тема: Re: [SQL] EXTERNAL storage and substring on long strings
Дата: ,
Msg-id: 1060014341.1434.53.camel@localhost.localdomain
(см: обсуждение, исходный текст)
Ответ на: Re: [SQL] EXTERNAL storage and substring on long strings  (Tom Lane)
Ответы: Re: [SQL] EXTERNAL storage and substring on long strings  (Joe Conway)
Список: pgsql-performance

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EXTERNAL storage and substring on long strings  (Scott Cain, )
 Re: EXTERNAL storage and substring on long strings  (Scott Cain, )
  Re: EXTERNAL storage and substring on long strings  (Tom Lane, )
  Re: EXTERNAL storage and substring on long strings  (Joe Conway, )
 Re: EXTERNAL storage and substring on long strings  (Scott Cain, )
  Re: EXTERNAL storage and substring on long strings  (Tom Lane, )
 Re: EXTERNAL storage and substring on long strings  (Joe Conway, )
  Re: EXTERNAL storage and substring on long strings  (Ron Johnson, )
   Re: EXTERNAL storage and substring on long strings  (Scott Cain, )
    Re: [SQL] EXTERNAL storage and substring on long strings  (Tom Lane, )
     Re: [SQL] EXTERNAL storage and substring on long strings  (Scott Cain, )
      Re: [SQL] EXTERNAL storage and substring on long strings  (Joe Conway, )
       Re: [SQL] EXTERNAL storage and substring on long strings  (Scott Cain, )
        Re: [SQL] EXTERNAL storage and substring on long strings  (Scott Cain, )
         Re: [SQL] EXTERNAL storage and substring on long strings  (Joe Conway, )
     Re: [SQL] EXTERNAL storage and substring on long strings  (Jan Wieck, )
      Re: [SQL] EXTERNAL storage and substring on long strings  (Tom Lane, )
       Re: [SQL] EXTERNAL storage and substring on long strings  (Scott Cain, )
       Re: [SQL] EXTERNAL storage and substring on long strings  (Jan Wieck, )
    Re: [SQL] EXTERNAL storage and substring on long strings  (Richard Huxton, )
     Re: [SQL] EXTERNAL storage and substring on long strings  (Scott Cain, )
      Re: [SQL] EXTERNAL storage and substring on long strings  ("Shridhar Daithankar", )
      Re: [SQL] EXTERNAL storage and substring on long strings  ("Matt Clark", )
  Re: EXTERNAL storage and substring on long strings  (Scott Cain, )
 Re: EXTERNAL storage and substring on long strings  (Tom Lane, )
 Re: EXTERNAL storage and substring on long strings  (Joe Conway, )
  Re: EXTERNAL storage and substring on long strings  (Scott Cain, )
 Re: EXTERNAL storage and substring on long strings  (Tom Lane, )
  Re: EXTERNAL storage and substring on long strings  (Joe Conway, )
   Re: EXTERNAL storage and substring on long strings  (Tom Lane, )
    Re: EXTERNAL storage and substring on long strings  (Scott Cain, )

On Mon, 2003-08-04 at 11:53, Tom Lane wrote:
> Scott Cain <> writes:
> > At least this appears to work and is much faster, completing substring
> > operations like above in about 0.27 secs (that's about two orders of
> > magnitude improvement!)
>
> I find it really, really hard to believe that a crude reimplementation
> in plpgsql of the TOAST concept could beat the built-in implementation
> at all, let alone beat it by two orders of magnitude.
>
> Either there's something unrealistic about your testing of the
> dna_string function, or your original tests are not causing TOAST to be
> invoked in the expected way, or there's a bug we need to fix.  I'd
> really like to see some profiling of the poor-performing
> external-storage case, so we can figure out what's going on.
>
I was really hoping for a "Good job and glad to hear it" from you :-)

I don't think there is anything unrealistic about my function or its
testing, as it is very much along the lines of the types of things we do
now.  I will really try to do some profiling this week to help figure
out what is going on.

Scott

--
------------------------------------------------------------------------
Scott Cain, Ph. D.                                         
GMOD Coordinator (http://www.gmod.org/)                     216-392-3087
Cold Spring Harbor Laboratory



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