Well, 16MB is 2K pages, which is what you'd get if 100 connections were all blocked and we're doing 20 pages per waiter. That seems like a really extreme scenario, so maybe 4MB is a good compromise. That's unlikely to be hit in most cases, unlikely to put a ton of stress on IO, even with magnetic media (assuming the whole 4MB is queued to write in one shot...). 4MB would still reduce the number of locks by 500x.
In my performance results given up thread, we are getting max performance at 32 clients, means at a time we are extending 32*20 ~= max (600) pages at a time. So now with 4MB limit (max 512 pages) Results will looks similar. So we need to take a decision whether 4MB is good limit, should I change it ?
