Re: How to avoid transaction ID wrap

On Fri, Jun 09, 2006 at 06:20:21PM -0700, Trent Shipley wrote:
> Ideally, the transaction management system would be proportional to the
> marginal change in size of the database rather than the gross size of the
> database. That is VACCUM being O(N) should be replaced (or there should be
> an optional alternative) that scales with D, O^k(D) where any k > 1 involves
> a tradeoff with VACCUM.

That's something that's been discussed quite a bit; search the archives
for 'dead space map'. Granted, that wasn't targeted so much at the need
to VACUUM FREEZE, but there's no reason it wouldn't be possible to make
it handle that as well. In the mean time, if you partition the table on
date, you won't need to be vacuuming the entire database to handle XID
wrap.

BTW, you're also ignoring the fact that technology keeps improving the
hardware that's out there. It's possible that hardware advances alone
would keep pace with your vacuuming needs.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461