Is there an exhaustive list of what takes what locks and how long they last? I'm asking because we just had some trouble doing a hot db change to an 8.3.6 system. I know it is an old version but it is what I have to work with.
There haven't been any major changes in this area since then, it wouldn't really matter if you were on a newer version. The short answer to your question is that no, there is no such list. The documentation at http://www.postgresql.org/docs/current/interactive/explicit-locking.html and http://www.postgresql.org/docs/current/interactive/view-pg-locks.html are unfortunately as good as it gets right now. The subject is a bit more complicated even than it appears at first, given that you don't just need to take into account what statement is executing. You need to know things like whether any foreign keys are involved as well as what index type is used (see http://www.postgresql.org/docs/current/interactive/locking-indexes.html ) to fully predict what the locking situation for your SQL is going to become. It's a fairly big grid of things to take into account.