| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | John Lumby <johnlumby(at)hotmail(dot)com> |
| Cc: | Claudio Freire <klaussfreire(at)gmail(dot)com>, greg(at)2ndquadrant(dot)com, pgsql hackers <pgsql-hackers(at)postgresql(dot)org>, Cédric Villemain <cedric(at)2ndquadrant(dot)com> |
| Subject: | Re: [PATCH] Prefetch index pages for B-Tree index scans |
| Date: | 2012-11-05 20:39:04 |
| Message-ID: | 20121105203904.GA19099@momjian.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Fri, Nov 2, 2012 at 09:59:08AM -0400, John Lumby wrote:
> Thanks for the mentioning this posting. Interesting.
> However, the OP describes an implementation based on libaio.
> Today what we have (for linux) is librt, which is quite different.
> It is arguable worse than libaio (well actually I am sure it is worse)
> since it is essentially just an encapsulation of using threads to do
> synchronous ios - you can look at it as making it easier to do what the
> application could do itself if it set up its own pthreads. The linux
> kernel does not know about it and so the CPU overhead of checking for
> completion is higher.
Well, good thing we didn't switch to using libaio, now that it is gone.
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2012-11-05 20:40:12 | Re: Doc patch, distinguish sections with an empty row in error code table |
| Previous Message | Tom Lane | 2012-11-05 20:30:32 | Re: Pg_upgrade speed for many tables |