On Tue, Aug 15, 2006 at 02:15:05PM -0500, Jim C. Nasby wrote:
>Now, if
>fsync'ing a file also ensures that all the metadata is written, then
>we're probably fine...
...and it does. Unclean shutdowns cause problems in general because
filesystems operate asynchronously. postgres (and other similar
programs) go to great lengths to make sure that critical operations are
performed synchronously. If the program *doesn't* do that, metadata
journaling isn't a magic wand which will guarantee data integrity--it
won't. If the program *does* do that, all the metadata journaling adds
is the ability to skip fsck and start up faster.
Mike Stone