Re: Load distributed checkpoint
От | Takayuki Tsunakawa |
---|---|
Тема | Re: Load distributed checkpoint |
Дата | |
Msg-id | 00cd01c7255f$80d1ea70$19527c0a@OPERAO обсуждение исходный текст |
Ответ на | Re: Load distributed checkpoint ("Zeugswetter Andreas ADI SD" <ZeugswetterA@spardat.at>) |
Ответы |
Re: Load distributed checkpoint
|
Список | pgsql-hackers |
----- Original Message ----- From: "Zeugswetter Andreas ADI SD" <ZeugswetterA@spardat.at> To: "Takayuki Tsunakawa" <tsunakawa.takay@jp.fujitsu.com>; "ITAGAKI Takahiro" <itagaki.takahiro@oss.ntt.co.jp> > > Yes, I used half the size of RAM as the shared buffers, which is > > reasonable. And I cached all the data. > For pg, half RAM for shared_buffers is too much. The ratio is good for > other db software, that does not use the OS cache. What percentage of RAM is recommended for shared buffers in general? 40%? 30%? Or, is the general recommendation like "According to the amount of your data, this much RAM should be left for the kernel cache. But tha's the story on Linux. It may be different for other OSes."? Hmm, if it is so, it sounds hard for system designers/administrators to judge. ----- Original Message ----- From: "Zeugswetter Andreas ADI SD" <ZeugswetterA@spardat.at> To: "Takayuki Tsunakawa" <tsunakawa.takay@jp.fujitsu.com>; "ITAGAKI Takahiro" <itagaki.takahiro@oss.ntt.co.jp> Cc: <pgsql-hackers@postgresql.org> Sent: Thursday, December 21, 2006 11:04 PM Subject: RE: [HACKERS] Load distributed checkpoint > > You were running the test on the very memory-depend machine. > >> shared_buffers = 4GB / The scaling factor is 50, 800MB of data. > > Thet would be why the patch did not work. I tested it with DBT-2, 10GB of > > data and 2GB of memory. Storage is always the main part of performace here, > > even not in checkpoints. > > Yes, I used half the size of RAM as the shared buffers, which is > reasonable. And I cached all the data. For pg, half RAM for shared_buffers is too much. The ratio is good for other db software, that does not use the OS cache. Andreas
В списке pgsql-hackers по дате отправления: