FWIW I don't think any amount of process would have gotten multixact to
not have the copious bugs it had. It was just too complex a patch,
doing ugly things to parts too deeply linked to the inner guts of the
server. We might have spared a few with some extra testing (such as the
idiotic wraparound bugs, and perhaps the pg_upgrade problems), but most
of the rest of it would have taken a real production load to notice --
which is exactly what happened.
(Of course, review from Tom might have unearthed many of these bugs
before they hit final release, but we're saying we don't want to be
dependent on Tom's review for every patch so that doesn't count.)
Review is good, but (as history shows) some bugs can slip through even
extensive review such as the one multixacts got from Noah and Andres.
Had anyone put some real stress on the beta, we could have noticed some
of these bugs much earlier. One of the problems we have is that our
serious users don't seem to take the beta period seriously. All our
users are too busy for that, it seems, and they expect that "somebody
else will test the point-zero release", and that by the time it hits
point-one or point-two it will be bug-free, which is quite clearly not
the case.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services