From: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> |
---|---|
To: | "Marc G(dot) Fournier" <scrappy(at)hub(dot)org> |
Cc: | Neil Conway <neilc(at)samurai(dot)com>, Sean Chittenden <sean(at)chittenden(dot)org>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: Bumping block size to 16K on FreeBSD... |
Date: | 2003-08-30 15:54:33 |
Message-ID: | 200308301554.h7UFsXs08328@candle.pha.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Marc G. Fournier wrote:
> Now, here's a question for someone running a non-FreeBSD OS ... if we were
> to jump the BLCKSZ to 16k, would it cause a degradation in performance, or
> would it make no difference to them? Would they see an 8% reduction in
> performance?
>
> The thing is ... there has been presented a strong, valid reason for
> moving to 16k (at least under FreeBSD) ... and there has been a valid
> reason for not making it "easily configurable" ... but, are there any
> strong reasons not to just move to 16k across the board?
First, I assume all this discussion about default block size is for 7.5,
not for 7.4, which is in beta. Second, the tests were done only for
_write_ performance. We can expect random read performance to be worse
for larger block sizes, so I think more research needs to be done.
Also, Tatsuo reported years ago that he got ~15% performance improvement
with a 32k PostgreSQL block size. The OS was AIX or Linux.
--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From | Date | Subject | |
---|---|---|---|
Next Message | ohp | 2003-08-30 15:55:22 | Re: Index creation takes for ever |
Previous Message | Bruce Momjian | 2003-08-30 15:42:45 | Re: massive quotes? |