Alvaro Herrera <[EMAIL PROTECTED]> writes: > Peter Schuller wrote: >> Even with the fix the lock is held. Is the operation expected to be >> "fast" (for some definition of "fast") and in-memory, or is this >> something that causes significant disk I/O and/or scales badly with >> table size or similar?
> It is fast. Well, it's *normally* fast. In a situation where there are a whole lot of empty pages at the end of the table, it could be slow. That's probably not very likely on a heavily used table. One should also note that (1) The only way vacuum will be able to obtain an exclusive lock in the first place is if there are *no* other transactions using the table at the time. (2) If it's autovacuum we're talking about, it will get kicked off the table if anyone else comes along and wants a conflicting lock. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance