Postgres Pro
Downloads
Home   >   mailing lists

Re: Direct I/O issues - Mailing list pgsql-performance

From Tom Lane
Subject Re: Direct I/O issues
Date
Msg-id 14171.1164300342@sss.pgh.pa.us
Whole thread Raw
In response to Direct I/O issues  (Greg Smith <gsmith@gregsmith.com>)
Responses Re: Direct I/O issues
List pgsql-performance
Tree view 
Greg Smith <gsmith@gregsmith.com> writes:
> The results I get now look fishy.

There are at least two things wrong with this program:

* It does not respect the alignment requirement for O_DIRECT buffers
  (reportedly either 512 or 4096 bytes depending on filesystem).

* It does not check for errors (if it had, you might have realized the
  other problem).

            regards, tom lane

pgsql-performance by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: Lying drives [Was: Re: Which OS provides the
Next
From: Greg Smith
Date:
Subject: Re: Direct I/O issues