Nice article, but doesn't actually demonstrate that connections setup and tear down is the bottleneck. If you really have 500 active connections all "shouting" at the database simultaneously, the fact that those connections were obtained from a pool or not isn't going to change the throughput of the database.

Pooling introduces numerous other issues as well. For example, clients probably shouldn't all be using the same entitlements to connect, right? Surely there are some segregation of duties and roles that clients will be using alternative entitlements into the system?

Finally, you have to show some before and after results. This article simply asserts that connection pooling would improve the situation, but does nothing to demonstrate the point. Even the details of the server matter...how many cpus, how many drives, HDD or flash, what file system is being used?