> > The predicate for files we MUST (fuzzy) copy is: 
> >   File exists at start of backup && File exists at end of backup
> 
> Right, which seems to me to negate all these claims about needing a
> (horribly messy) way to read uncommitted system catalog entries, do
> blind reads, etc.  What's wrong with just exec'ing tar after having
> done a checkpoint?

Right.

It looks like insert/update/etc ops over local relations are
WAL-logged, and it's Ok (we have to do this).

So, we only have to use shared buffer pool for local (but probably
not for temporary) relations to close this issue, yes? I personally
don't see any performance issues if we do this.

Vadim

Fri, 2 Aug 2002 13:55:19 -0700 
"Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
Re: PITR, checkpoint, and local relations 
"Mikheev, Vadim" <vmikheev@SECTORBASE.COM> writes:
> So, we only have to use shared buffer pool for local (but probably
> not for temporary) relations to close this issue, yes? I personally
> don't see any performance issues if we do this.

Hmm.  Temporary relations are a whole different story.

It would be nice if updates on temp relations never got WAL-logged at
all, but I'm not sure how feasible that is.  Right now we don't really
distinguish temp relations from ordinary ones --- in particular, they
have pg_class entries, which surely will get WAL-logged even if we
persuade the buffer manager not to do it for the data pages.  Is that
a problem?  Not sure.

			regards, tom lane

Fri, 02 Aug 2002 17:29:09 -0400
Tom Lane <tgl@sss.pgh.pa.us>
Re: PITR, checkpoint, and local relations 