On Dec 12, 2007 9:46 AM, Collin Kidder <adderd@xxxxxxxxx> wrote: > Magicloud Wang wrote: > > Dear, > > I think database has its own operation journal, and different journal > > filesystem does give different performance. So if I put database file on a > > non-journal filesystem, would it be safe? Does this like using a raw device? > > > > > > > You lose a little bit of data integrity in exchange for a little bit of > speed. I suppose it'd be a fine thing to do so long as you can live with > that trade off. If you want good data integrity you are more likely to > get it from battery backed RAID5 or RAID10 or something of that sort > rather than just trusting something like EXT3 or Reiser. EXT2 isn't a > bad file system. It's one of things where the known bugs in ext2/3 aren't as bad as they sound, while the unknown bugs in some newer, less tested file systems are often worse. OTOH, ext2/3 do have a 2 TB partition size limit (or at least used to) so for some things, you just gotta go to a different file system. Back to the subject at hand, do you need journaling for the db, this thread from last year has a lot of good info in it. It's the one where I got the impression that ext2 for pg_xlog was fine and dandy. I remember now, after reading it, that certain types of fsync might be dangerous with non-journaled file systems. http://archives.postgresql.org/pgsql-performance/2006-08/msg00101.php ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
