Thread

1. Re: PITR, checkpoint, and local relations

   Vadim Mikheev <vmikheev@sectorbase.com> — 2002-08-02T20:55:19Z

   > > 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
   
   

2. Re: PITR, checkpoint, and local relations

   Tom Lane <tgl@sss.pgh.pa.us> — 2002-08-02T21:29:09Z

   "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