Re: Additional background daemon (was: Remove xmin and cmin from frozen tuples) - Mailing list pgsql-hackers

From Jim C. Nasby
Subject Re: Additional background daemon (was: Remove xmin and cmin from frozen tuples)
Date
Msg-id 20050902035131.GC20265@pervasive.com
Whole thread Raw
In response to Re: Additional background daemon (was: Remove xmin and cmin from frozen tuples)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Thu, Sep 01, 2005 at 11:22:07PM -0400, Tom Lane wrote:
> "Jim C. Nasby" <jnasby@pervasive.com> writes:
> > On Thu, Sep 01, 2005 at 09:22:35AM -0400, Tom Lane wrote:
> >> This is a bad idea.  The bgwriter isn't the place to be doing freezing,
> 
> > So is this something that another daemon could handle?
> 
> Possibly, but I'd be inclined to think of it as autovacuum's problem.

Possibly, although what tends to make bgwriter interesting for these
things is that we want to perform some operation on pages between when
they get modified and when they get written out to disk. AFAIK
autovacuum wouldn't currently serve that purpose (though I could be
wrong). In any case, the big point is that there are ideas out there
that might warrant an additional daemon besides bgwriter (my
recollection is that this isn't the first proposal that's been objected
to on the basis of bgwriter being the wrong place to do something).
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software        http://pervasive.com        512-569-9461


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