Bruce Momjian <pgman@candle.pha.pa.us> writes:
> You need something that works from the command line, and something that
> works if PostgreSQL is not running. How would you restore one file from
> a tape.
"Restore one file from a tape"? How are you going to do that anyway?
You can't save and restore portions of a database like that, because
of transaction commit status problems. To restore table X correctly,
you'd have to restore pg_log as well, and then your other tables are
hosed --- unless you also restore all of them from the backup. Only
a complete database restore from tape would work, and for that you
don't need to tell which file is which. So the above argument is a
red herring.
I realize it's nice to be able to tell which table file is which by
eyeball, but the price we are paying for that small convenience is
just too high. Give that up, and we can have rollbackable DROP and
RENAME now (I'll personally commit to making it happen for 7.1).
Continue to insist on it, and I don't think we'll *ever* have those
features in a really robust form. It's just not possible to do
multiple file renames atomically.
regards, tom lane