Re: How to avoid transaction ID wrap

On Wed, Jun 07, 2006 at 11:47:45AM -0400, Tom Lane wrote:
> Zdenek Kotala <Zdenek.Kotala@Sun.COM> writes:
> > Koichi Suzuki wrote:
> >> I've once proposed a patch for 64bit transaction ID, but this causes 
> >> some overhead to each tuple (XMIN and XMAX).
> 
> > Did you check performance on 32-bit or 64-bit systems and 64-bit binary 
> > version of PGSQL? I think that today is not problem to have 64-bit 
> > architecture and 64-bit ID should increase scalability of Postgres.
> 
> The percentage increase in I/O demand is the main reason the patch was
> rejected, not so much the arithmetic.

Before considering 64 bit XIDs, it'd be very helpful to know why Mark
can't vacuum frequently enough to handle rollover...
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
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