Re: 15,000 tables

Agreed, and I apologize for the imprecision of my post below.

I should have written:
"Best practice seems to be to use a journaling fs and log metadata
only and put it on separate dedicated spindles."

I've seen enough HD failures that I tend to be paranoid and log the
metadata of fs dedicated to WAL as well, but that may very well be overkill.

Ron

At 01:57 PM 12/1/2005, Tom Lane wrote:
>Ron <rjpeace@earthlink.net> writes:
> > Agreed.  Also the odds of fs corruption or data loss are higher in a
> > non journaling fs.  Best practice seems to be to use a journaling fs
> > but to put the fs log on dedicated spindles separate from the actual
> > fs or pg_xlog.
>
>I think we've determined that best practice is to journal metadata only
>(not file contents) on PG data filesystems.  PG does expect the filesystem
>to remember where the files are, so you need metadata protection, but
>journalling file content updates is redundant with PG's own WAL logging.
>
>On a filesystem dedicated to WAL, you probably do not need any
>filesystem journalling at all --- we manage the WAL files in a way
>that avoids changing metadata for a WAL file that's in active use.
>A conservative approach would be to journal metadata here too, though.
>
>                         regards, tom lane