It may not always be the database that is the bottleneck or slowest component of all the collective pieces that exist between the client and the application. If testing shows the database to be operating within normal benchmark limits (properly tuned), then it is time to take a look at other most-encountered performance issues. Note that some of these are Oracle components, some of them are not. Get your system administrator involved early on whenever there is a system-wide slowness problem, such as:
Slow or busy server
Underlying network
TNS Listener hanging (see MOS document in the box)
Shared server (also known as Multi-threaded server)—related issues
Properly functioning application
Advanced networking option—encryption
Transparent gateways
Connection manager