Don Baccus <dhogaza@pacifier.com> writes:
> 5. The semantics of VACUUM have changed. Silently (in the sense that
> there's no notification or warning spewed out).
??? VACUUM has no semantics: it does not alter your data (or at least
it's not supposed to ;-)). This change is transparent in the same
way that the WAL and function manager changes were. If there is any
lack of transparency, it would show up as greater disk space usage
than you might expect --- which seems *exactly* parallel to WAL.
And you don't have the option to turn WAL off. I don't think you
can consistently maintain that adding WAL is good and changing VACUUM
is bad.
> Or if the new one hoses your tables. Tom's bright, but he's not
> certified bug-free.
Certainly, but you are assuming that the old VACUUM is bug-free,
which is, um, overly optimistic. The new VACUUM code is (mostly) a
subset of the old, and has removed all the most ticklish bits of the old
code. So if you are looking for the fewest bugs you should prefer the
new to the old anyway. Case in point: Brian Hirt's bug does not arise
under new-style VACUUM. I had to say VACUUM FULL to make it happen
in current sources.
regards, tom lane
