RE: RE: [COMMITTERS] pgsql/src/backend/access/transam ( xact.c xlog.c)

> > Can you tell me how to use CHECKPOINT please?
>
> You shouldn't normally use it - postmaster will start backend
> each 3-5 minutes to do this automatically.

Oh, I see.

> > > > Is this the same as a SAVEPOINT?
> > >
> > > No. Checkpoints are to speedup after crash recovery and
> > > to remove/archive log files. With WAL server doesn't write
> > > any datafiles on commit, only commit record goes to log
> > > (and log fsync-ed). Dirty buffers remains in memory long

Ok, so with CHECKPOINTS, we could move the offline log files to
somewhere else so that we could archive them, in my
undertstanding. Now question is, how we could recover from disaster
like losing every table files except log files. Can we do this with
WAL? If so, how can we do it?

> > Is log fsynced even I turn of -F?
>
> Yes, though we can change this. We also can implement now
> feature that Bruce wanted so long and so much -:) -
> fsync log not on each commit but each ~ 5sec, if
> losing some recent commits is acceptable.

Sounds great.
--
Tatsuo Ishii