Re: PITR, checkpoint, and local relations

> -----Original Message-----
> From: J. R. Nield [mailto:jrnield@usol.com]
> Sent: Monday, August 05, 2002 12:58 PM
> To: Bruce Momjian
> Cc: Tom Lane; Christopher Kings-Lynne; Richard Tucker; PostgreSQL Hacker
> Subject: Re: [HACKERS] PITR, checkpoint, and local relations
>
>
> This is great Tom. I will try to get what I have to you, Vadim, and
> other interested parties tonight (Mon), assuming none of my tests fail
> and reveal major bugs. It will do most of the important stuff except
> your changes to the local buffer manager. I just have a few more minor
> tweaks, and I would like to test it a little first.
>
> On your advice I have made it use direct OS calls to copy the files,
> using BLCKSZ aligned read() requests, instead of going through the
> buffer manager for reads. I can think more about the correctness of this
> later, since the rest of the code doesn't depend on which method is
> used.
>
> To Richard Tucker: I think duplicating the WAL files the way you plan is
> not the way I want to do it. I'd rather have a log archiving system be
> used for this. One thing that does need to be done is an interactive
> recovery mode, and as soon as I finish getting my current work out for
> review I'd be glad to have you write it if you want. You'll need to see
> this in order to interface properly.

If you don't duplicate(mirror) the log then in the event you need to restore
a database with roll forward recovery won't the restored database be missing
on average 1/2 a log segments worth of changes?

>
> Regards,
>
>   John Nield
>
> On Sat, 2002-08-03 at 22:52, Bruce Momjian wrote:
> >
> > Sounds like a win all around; make PITR easier and temp tables faster.
> >
> >
> >
> ------------------------------------------------------------------
> ---------
> >
> > Tom Lane wrote:
> > > These changes seem very attractive to me even without regard
> for making
> > > the world safer for PITR.  I'm willing to volunteer to make
> them happen,
> > > if there are no objections.
> > >
> > >             regards, tom lane
> > >
> >
> > --
> >   Bruce Momjian                        |  http://candle.pha.pa.us
> >   pgman@candle.pha.pa.us               |  (610) 853-3000
> >   +  If your life is a hard drive,     |  830 Blythe Avenue
> >   +  Christ can be your backup.        |  Drexel Hill,
> Pennsylvania 19026
> >
> --
> J. R. Nield
> jrnield@usol.com
>
>
>