Re: SAN/NAS options - Mailing list pgsql-performance

From Michael Stone
Subject Re: SAN/NAS options
Date
Msg-id 20051216225103.GE2883@mathom.us
Whole thread Raw
In response to Re: SAN/NAS options  ("Jim C. Nasby" <jnasby@pervasive.com>)
Responses Re: SAN/NAS options  ("Jim C. Nasby" <jnasby@pervasive.com>)
List pgsql-performance
On Fri, Dec 16, 2005 at 04:18:01PM -0600, Jim C. Nasby wrote:
>Even if you're doing a lot of random IO? I would think that random IO
>would perform better if you use smaller (8K) blocks, since there's less
>data being read in and then just thrown away that way.

The overhead of reading an 8k block instead of a 32k block is too small
to measure on modern hardware. The seek is what dominates; leaving the
read head on a little longer and then transmitting a little more over a
200 megabyte channel is statistical fuzz.

Mike Stone

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