Re: [HACKERS] Re: v7.1b4 bad performance

Поиск
Список
Период
Сортировка
От Tatsuo Ishii
Тема Re: [HACKERS] Re: v7.1b4 bad performance
Дата
Msg-id 20010224113813L.t-ishii@sra.co.jp
обсуждение исходный текст
Ответ на Re: [HACKERS] Re: v7.1b4 bad performance  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-admin
> Okay, plan B then: let's ask people to redo their benchmarks with
> -s bigger than one.  Now, how much bigger?
>
> To the extent that you think this is a model of a real bank, it should
> be obvious that the number of concurrent transactions cannot exceed the
> number of tellers; there should never be any write contention on a
> teller's table row, because only that teller (client) should be issuing
> transactions against it.  Contention on a branch's row is realistic,
> but not from more clients than there are tellers in the branch.
>
> As a rule of thumb, then, we could say that the benchmark's results are
> not to be believed for numbers of clients exceeding perhaps 5 times the
> scale factor, ie, half the number of teller rows (so that it's not too
> likely we will have contention on a teller row).

At least -s 5 seems reasonable for me too. Maybe we should make it as
the default setting for pgbench?
--
Tatsuo Ishii

В списке pgsql-admin по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: select * from pgadmin_users; causes error
Следующее
От: Dave Page
Дата:
Сообщение: RE: select * from pgadmin_users; causes error