Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Hannu Krosing <hannu@skype.net>
From: Hannu Krosing <hannu@skype.net>
To: Martijn van Oosterhout <kleptog@svana.org>
Cc: Bruce Momjian <pgman@candle.pha.pa.us>, Simon Riggs <simon@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Greg Stark <gsstark@mit.edu>, Rod Taylor <pg@rbt.ca>, Qingqing Zhou <zhouqq@cs.toronto.edu>, pgsql-hackers@postgresql.org
Date: 2005-12-27T22:47:31Z
Lists: pgsql-hackers
Ühel kenal päeval, T, 2005-12-27 kell 19:20, kirjutas Martijn van Oosterhout: > On Mon, Dec 26, 2005 at 11:00:51AM -0500, Bruce Momjian wrote: > > > > I think this brings up an interesting distinction, that having the NO > > LOGGING switch per command doesn't make sense because it modifying the > > table. It has to be a per-object switch, or something that operates > > only on empty tables. This is the exact same distinction we talked > > about for NO LOGGING COPY. > > I've thought of one other possibility, which is kind of at the extreme > end of system implementation. Given the suggestion about not losing a > whole table on unclean shutdown, how about using a single table, split. > > 1. When setting no logging flag, take exclusive lock and record > filesize. This size is X. > 2. From now on any data before X is read-only. So no updates. Any new > data needs to be allocated at end, so no FSM either. > 3. Any data added after X is not logged to xlog. > 4. On unclean shutdown, truncate table to length X. > 5. When logging is reenabled, set X back to infinity. How would it work for indexes ? ------------ Hannu