On Wed, 2002-07-03 at 16:30, Tom Lane wrote: > My guess is that the actual volume of data going through the notify > mechanism isn't going to be all that large, and so avoiding one memcpy > step for it isn't going to be all that exciting.
It may become large if we will have an implementation which can cope well with lage volumes :) > I think I'd lean towards minimizing the time spent holding the > shared lock, instead. In case you are waiting for just one message out of 1000 it may still be faster to do selective copying. It is possible that 1000 strcmp's + 1000 pointer traversals are faster than one big memcpy, no ? > But it's a judgment call. If we have a clean C interface + separate PG binding we may write several different modules for different scenarios and let the user choose (even at startup time) - code optimized for messages that everybody wants is bound to be suboptimal for case when they only want 1 out of 1000 messages. Same for different message sizes. ------------- Hannu ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
