From: | Zeugswetter Andreas SB <ZeugswetterA(at)wien(dot)spardat(dot)at> |
---|---|
To: | "'Tom Lane'" <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | "'Hiroshi Inoue'" <Inoue(at)tpf(dot)co(dot)jp>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | AW: AW: AW: AW: Vacuum only with 20% old tuples |
Date: | 2000-07-27 08:09:29 |
Message-ID: | 11C1E6749A55D411A9670001FA687963368031@sdexcsrv1.f000.d0188.sd.spardat.at |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
> Zeugswetter Andreas SB <ZeugswetterA(at)wien(dot)spardat(dot)at> writes:
> >> If there are no more records, then you are reduced to
> guessing whether
> >> you have to undo the rename or not. If you guess wrong,
> you leave the
> >> database in a corrupted state.
>
> > If the original filename exists the rename failed else it succeeded.
>
> That's exactly the unreliable assumption I do not want to make.
>
> > The backends could not have created a new file of the old name
> > after "starting rename" beeing last log record.
>
> So you're assuming that we fsync() the log after *each* item is added?
> *Within* a transaction? fsync only at end of xact was the plan,
> I believe.
With trx log we imho would not need any fsyncs anymore
(except maybe checkpoints).
We would open the trxlog file with O_SYNC and only do a write
when it is absolutely necessary (buffer overflow, end of trx).
But yes the rename log entries (only those) would need to be
written immediately. Is this a performance issue? I guess not.
Andreas
From | Date | Subject | |
---|---|---|---|
Next Message | Zeugswetter Andreas SB | 2000-07-27 08:21:47 | AW: TOAST & vacuum |
Previous Message | frank | 2000-07-27 06:39:54 | Re: [GENERAL] Is Pg 7.0.x's Locking Mechanism BROKEN? |