Re: [PERFORM] 8.2 Autovacuum BUG ?

On 8/31/07, Alvaro Herrera <alvherre@commandprompt.com> wrote:
>
> Pallav Kalva wrote:
> > Tom Lane wrote:
>
> >> Probably represents freezing of old tuples, which is a WAL-logged
> >> operation as of 8.2. Is it likely that the data is 200M transactions
> >> old?
> >>
> > If nothing changed on these tables how can it freeze old tuples ?
> > Does it mean that once it reaches 200M transactions it will do the same
> > thing all over again ?
>
> No -- once tuples are frozen, they don't need freezing again (unless
> they are modified by UPDATE or DELETE).
>
>

Off-topic question: the documentation says that XID numbers are 32 bit. Could the XID be 64 bit when running on a 64 bit platform? That would effectively prevent wrap-around issues.

Regards

MP Received on Fri Aug 31 14:34:11 2007