Re: BUG #4919: CREATE USER command slows down system performance

От: Alvaro Herrera
Тема: Re: BUG #4919: CREATE USER command slows down system performance
Дата: ,
Msg-id: 20090715140209.GF4551@alvh.no-ip.org
(см: обсуждение, исходный текст)
Ответ на: Re: BUG #4919: CREATE USER command slows down system performance  ("Lauris Ulmanis")
Ответы: Re: BUG #4919: CREATE USER command slows down system performance  (toruvinn)
Re: BUG #4919: CREATE USER command slows down systemperformance  ("Lauris Ulmanis")
Список: pgsql-bugs

Скрыть дерево обсуждения

BUG #4919: CREATE USER command slows down system performance  ("Lauris Ulmanis", )
 Re: BUG #4919: CREATE USER command slows down system performance  (Heikki Linnakangas, )
  Re: BUG #4919: CREATE USER command slows down system performance  ("Lauris Ulmanis", )
   Re: BUG #4919: CREATE USER command slows down system performance  (Alvaro Herrera, )
    Re: BUG #4919: CREATE USER command slows down system performance  (toruvinn, )
     Re: BUG #4919: CREATE USER command slows down system performance  (Alvaro Herrera, )
      Re: BUG #4919: CREATE USER command slows down system performance  (Tom Lane, )
       Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Marko Kreen, )
        Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (David Wilson, )
         Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Tom Lane, )
         Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Marko Kreen, )
       Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Bruce Momjian, )
        Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Tom Lane, )
         Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Alvaro Herrera, )
          Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Tom Lane, )
           Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Tom Lane, )
            Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Alvaro Herrera, )
             Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Tom Lane, )
              Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Alvaro Herrera, )
               Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Tom Lane, )
         Re: [PERFORM] BUG #4919: CREATE USER command slows down system performance  (Bruce Momjian, )
    Re: BUG #4919: CREATE USER command slows down systemperformance  ("Lauris Ulmanis", )
 Re: BUG #4919: CREATE USER command slows down system performance  (Alvaro Herrera, )

Lauris Ulmanis wrote:
> Hello again!
>
> I did test on my local test server
>
> I created up 500 000 users in function loop very quickly - within 48
> seconds. I did again this script reaching up to 1 billion users - results
> was the same - 48 seconds. It is very quickly.
>
> But problem seems is with transaction preparation because if in database is
> 1 billion users and I want to create 1 new - it will take 4 seconds!
>
> After that I generated up to 2 billion users in this server (generation
> process took just 1.44 minutes of times - again quickly).
>
> And did 1 user creation again - now it took 9 seconds of time!
>
> What is a reason of this slowness? Is there a workaround or solution how to
> avoid it?

My bet is on the pg_auth flat file.  I doubt we have ever tested the
behavior of that code with 1 billion users ...

Do you really need 1 billion users?  Are you planning on giving accounts
to every human being in the planet or what?  I mean, what's the point of
this test?

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.


В списке pgsql-bugs по дате сообщения:

От: Alan Pinstein
Дата:
Сообщение: Re: BUG #4921: ltree @> ltree[] operator shouldn't fail if ltree[] is empty
От: "Jim Michaels"
Дата:
Сообщение: BUG #4924: pg_restore hangs, does nothing