Greg Stark <[EMAIL PROTECTED]> writes: > Tom Lane <[EMAIL PROTECTED]> writes: >> This sounds good until you think about locking. It'd be quite >> impractical to implement anything as fine-grained as EXPLAIN ANALYZE >> this way, because of the overhead involved in taking and releasing >> spinlocks.
> I'm not entirely convinced. The only other process that would be looking at > the information would be the statistics accumulator which would only be waking > up every 100ms or so. There would be no contention with other backends > reporting their info. The numbers I've been looking at lately say that heavy lock traffic is expensive, particularly on SMP machines, even with zero contention. Seems the cache coherency protocol costs a lot even when it's not doing anything... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster