Re: Bad n_distinct estimation; hacks suggested?

От: Dave Held
Тема: Re: Bad n_distinct estimation; hacks suggested?
Дата: ,
Msg-id: 49E94D0CFCD4DB43AFBA928DDD20C8F9026184BC@asg002.asg.local
(см: обсуждение, исходный текст)
Ответ на: Bad n_distinct estimation; hacks suggested?  (Josh Berkus)
Список: pgsql-performance

Скрыть дерево обсуждения

Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
 Re: Bad n_distinct estimation; hacks suggested?  ("Dave Held", )
 Re: Bad n_distinct estimation; hacks suggested?  (Tom Lane, )
  Re: Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
   Re: Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
    Re: Bad n_distinct estimation; hacks suggested?  (Marko Ristola, )
     Re: Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
      Re: Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
       Re: Bad n_distinct estimation; hacks suggested?  (Greg Stark, )
        Re: Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
         Re: Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
         Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  ("Andrew Dunstan", )
         Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Tom Lane, )
          Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Marko Ristola, )
          Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Simon Riggs, )
           Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
           Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Andrew Dunstan, )
          Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Andrew Dunstan, )
         Re: Bad n_distinct estimation; hacks suggested?  (Simon Riggs, )
          Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Tom Lane, )
           Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Simon Riggs, )
            Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
             Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
             Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Andrew Dunstan, )
              Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Mischa Sandberg, )
               Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Andrew Dunstan, )
                Re: Distinct-Sampling (Gibbons paper) for Postgres  (, )
                 Re: Distinct-Sampling (Gibbons paper) for Postgres  (Josh Berkus, )
            Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Tom Lane, )
             Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Simon Riggs, )
              Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Gurmeet Manku, )
               Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Simon Riggs, )
              Citation for "Bad n_distinct estimation; hacks suggested?"  (Gurmeet Manku, )
               Foreign key constraints compile faster in 7.4  (Ashish Arte, )
                Re: Foreign key constraints compile faster in 7.4  (Tom Lane, )
 Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
 Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
  Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Tom Lane, )
 Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
  Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Mischa Sandberg, )
  Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Markus Schaber, )
   Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Mischa Sandberg, )
    Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
     Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (John A Meinel, )
      Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Josh Berkus, )
     Re: [HACKERS] Bad n_distinct estimation; hacks suggested?  (Mischa Sandberg, )

> -----Original Message-----
> From: Josh Berkus [mailto:]
> Sent: Tuesday, April 19, 2005 2:09 PM
> To: pgsql-perform
> Subject: [PERFORM] Bad n_distinct estimation; hacks suggested?
>
> [...]
> (BTW, increasing the stats to 1000 only doubles n_distinct,
> and doesn't solve the problem)

Speaking of which, is there a reason why statistics are limited
to 1000?  Performance?

__
David B. Held
Software Engineer/Array Services Group
200 14th Ave. East,  Sartell, MN 56377
320.534.3637 320.253.7800 800.752.8129


В списке pgsql-performance по дате сообщения:

От: "Jim C. Nasby"
Дата:
Сообщение: Slow copy with little CPU/disk usage
От: Tom Lane
Дата:
Сообщение: Re: Sort and index