| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Greg Smith <gsmith(at)gregsmith(dot)com> |
| Cc: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Direct I/O issues |
| Date: | 2006-11-23 16:45:42 |
| Message-ID: | 14171.1164300342@sss.pgh.pa.us |
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| Lists: | pgsql-hackers pgsql-patches pgsql-performance |
Greg Smith <gsmith(at)gregsmith(dot)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
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