Re: PITR, checkpoint, and local relations
Vadim Mikheev <vmikheev@sectorbase.com>
From: "Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
To: "'J. R. Nield'" <jrnield@usol.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Richard Tucker <richt@multera.com>, Bruce Momjian <pgman@candle.pha.pa.us>, PostgreSQL Hacker <pgsql-hackers@postgresql.org>
Date: 2002-08-02T22:00:46Z
Lists: pgsql-hackers
> > You don't need it. > > As long as whole block is saved in log on first after > > checkpoint (you made before backup) change to block. > > I thought half the point of PITR was to be able to turn > off pre-image logging so you can trade potential recovery Correction - *after*-image. > time for speed without fear of data-loss. Didn't we have > this discussion before? Sorry, I missed this. So, it's already discussed what to do about partial block updates? When system crashed just after LSN, but not actual tuple etc, was stored in on-disk block and on restart you compare log record' LSN with data block' LSN, they are equal and so you *assume* that actual data are in place too, what is not the case? I always thought that the whole point of PITR is to be able to restore DB fast (faster than pg_restore) *AND* up to the last committed transaction (assuming that log is Ok). Vadim