Re: [HACKERS] Hint Bits and Write I/O - Mailing list pgsql-patches

From Alvaro Herrera
Subject Re: [HACKERS] Hint Bits and Write I/O
Date
Msg-id 20080801231014.GM4321@alvh.no-ip.org
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In response to Re: [HACKERS] Hint Bits and Write I/O  (Simon Riggs <simon@2ndquadrant.com>)
Responses Re: [HACKERS] Hint Bits and Write I/O  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-patches
Simon Riggs wrote:

> The first "half" is actually quite large, but that makes it even more
> sensible to commit this part now.
>
> The enclosed patch introduces the machinery by which we might later
> optimise hint bit setting. It differentiates between hint bit setting
> and block dirtying, when the distinction can safely be made. It acts
> safely during VACUUM and correctly during checkpoint. In all other
> respects it emulates current behaviour.

I think it makes sense to commit this patch now, per previous
discussions on which we have agreed to make incremental changes.  I
think we should just get rid of the bogus changes Pavan identified.

I'm just wondering if the change of usage_count from 16 to 8 bits was
discussed and agreed?

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

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