Optimal Database Connection Pool Size

Question

I have read that you should keep the number of connections in your database connection pool lower than the number of threads running in the application server and that might use that pool correct? I have read too that having a high number of connections is not good but I don't really know why? Would it use more memory? Right now during pick times my server is running out of connections and I don't know it would be good just to increase the number of connections.

Thank you

Answer 1

With a Small Connection pool you have faster access on the connection table but may not have enough connections to satisfy requests.

In the other hand with a Large Connection pool there are more connections to fulfill requests and requests will spend less (or no) time in the queue but access on the connection table is slower.

http://docs.oracle.com/cd/E19316-01/820-4343/abehs/index.html

Answer 2

core_count = 4

connections = ((core_count * 2) + effective_spindle_count) = 9