Alvaro Herrera <[EMAIL PROTECTED]> writes: > I think if we want to do nontrivial manipulations in PGPROC we should > make sure it's properly locked. Maybe it's a good time to implement the > locking suggested here? With a LWLock instead of a spinlock, of course; > we would need MaxBackends extra LWLocks.
Given the performance issues we're currently seeing with spinlocks on SMP machines, I'm not sure I want to turn GetSnapshot from a get-one-lock operation into a get-one-lock-per-backend operation :-( The comment you were looking at was written on the assumption that grabbing a spinlock is cheap, but it seems it isn't ... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match