Bruce Momjian <[EMAIL PROTECTED]> writes: > Of course, this makes VACUUM run longer, and if you are waiting for it > to finish, it would be worse, like if you are running it at night or > something.
My plan was that the time delay would be a parameter and pg_autovacuum would set it based on the observed rate at which free space is accumulating. Someone could manually specify a delay, but by default it would run with no delay when run on the command line. > I think the delay has to take into account the number of active > transactions or something. That's a possibility. That's actually what the linux-kernel folk suggested. Someone there suggested using aio to do carefully schedule i/o only when no i/o was pending from transactions. But vacuum has no way to judge whether those transactions are really doing much disk i/o or only reading cached blocks, or even whether the disk i/o they're doing is on the same disk. They could also be waiting on the client or on locks from other transactions. -- greg ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
