Re: XFS filessystem for Datawarehousing

On Thu, Aug 03, 2006 at 01:10:39AM -0600, Koth, Christian (DWBI) wrote:
>For what reason are you planning to use a journaling FS? I think using WAL, fsyncing every transaction and using a journaling FS is tautologous. And if you have problems using EXT2 you can just add the journal later without loosing data.
>My tests using EXT2 showed a performance boost up to 50% on INSERTs.

The requirements for the WAL filesystem and for the data filesystem are
different. Having the WAL on a small ext2 filesystem makes sense and is
good for performance. Having the data on a huge ext2 filesystem is a
horrible idea, because you'll fsck forever if there's a crash, and
because ext2 isn't a great performer for large filesystems. I typically
have a couple-gig ext2 WAL paired with a couple of couple-hundred-gig
xfs data & index partitions. Note that the guarantees of a journaling fs
like xfs have nothing to do with the kind of journaling done by the WAL,
and each has its place on a postgres system.

Mike Stone