Re: VACUUMs and WAL

On Tue, 2008-10-28 at 11:45 +0200, Hannu Krosing wrote:
> On Tue, 2008-10-28 at 08:49 +0000, Simon Riggs wrote:
> > Looking at a VACUUM's WAL records makes me think twice about the way we
> > issue a VACUUM.
> > 
> > 1. First we scan the heap, issuing a HEAP2 clean record for every block
> > that needs cleaning.
> 
> IIRC the first heap pass just collects info and does nothing else. 
> Is this just an empty/do-nothing WAL record ?

8.3 changed that; it used to work that way. I guess I never looked at
the amount of WAL being generated.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support