Re: PrivateRefCount (for 8.3)

Added to TODO:

* Consider decreasing the amount of memory used by PrivateRefCount

http://archives.postgresql.org/pgsql-hackers/2006-11/msg00797.php
http://archives.postgresql.org/pgsql-hackers/2007-01/msg00752.php

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Simon Riggs wrote:
> On Mon, 2006-11-27 at 14:42 -0500, Bruce Momjian wrote:
> > Simon Riggs wrote:
> > > int8 still seems like overkjll. When will the ref counts go above 2 on a
> > > regular basis? Surely refcount=2 is just chance at the best of times.
> > >
> > > Refcount -> 2 bits per value, plus a simple overflow list? That would
> > > allow 0,1,2 ref counts plus 3 means look in hashtable to find real
> > > refcount.
> >
> > At two bits, would we run into contention for the byte by multiple
> > backends?
>
> No contention, its a private per-backend data structure. That's why we
> want to reduce the size of it so badly.
>
> --
> Simon Riggs
> EnterpriseDB http://www.enterprisedb.com
>
>
>
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--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://www.enterprisedb.com

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