On Wed, Oct 30, 2002 at 01:36:28AM +0100, Michiel Lange wrote: > I was just wondering about a few options that I would think might be pretty > useful. They might exist, but then, I don't know how to get it done... > > Here's my list: > - multi-volume database. Is it possible to split the complete database so it > will use several disks? One reason might be load-balancing of the disks, > another might be a very full disk... there may be even more... > - If multi-voluming exists, is it possible to make certain specific tables > can get in a special 'area', so you'd know on which disk it would be?
There have been several suggestions to implement this functionality, but it's been a relatively low priority, it seems. You can sort of mimic this with symlinks, but it's a pain to do. My suggestion is to throw money at a RAID configuration, instead. We've had very good luck with RAID 1+0. > - Every database system has a ROLLBACK function, also known as > 'before-imaging'. Postgres no doubt has this technique as well? How (which > file(s)) is this done in Postges, and how can you manage the size of these > before images? ROLLBACK is a feature of the transaction model in Postgres. You already have it; you need to initiate a transaction to get to it. Postgres does this with the WAL. You _do_ want to put the WAL files (which are in pg_xlog in your data directory) on another disk. You may do this with a symlink; SHUT DOWN YOUR DATABASE before you do it! Check out the WAL section of the manual for more details on how to use and configure the facility. > - In a situation of a crash, a rollback is a MUST. A rollforward is > desirable... does postgres offer this functionality as well? (I guess it > does) and the same question as the before-image arises as with this > so-called after-imaging. There is automatic recovery in the event of a crash, but you can't get point-in-time recovery yet. It's in the hopper for 7.4, apparently. > Oh... and does anyone know something about the relation Postgres and > Progress? the names seem so similar... Not as far as I know. There is an historical relationship between PostgreSQL, Postgres (which is actually different from PostgreSQL, and had a commercial variant in Illustra), and Ingres. See the history section of the manual for details. > and... do my questions sound stupid? ;-) No, but you might want to have a look at the manuals: there's a lot of info there. A -- ---- Andrew Sullivan 204-4141 Yonge Street Liberty RMS Toronto, Ontario Canada <[EMAIL PROTECTED]> M2P 2A8 +1 416 646 3304 x110 ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org