In a Nutshell


A database performance problem may easily be diagnosed if the DBA knows what each session is doing or has done in the database. In practice, however, a DBA normally administers many databases, and it is impossible to baby-sit each one. Therefore, a question such as, ‚“Why did the job run so slowly? ‚½ is challenging to even the most competent DBA. The Oracle Wait Interface is great at finding the root causes of performance problems, provided the DBA is aware of the bottlenecks. Tuning exercises without the guidance of bottlenecks (or symptoms) is almost always unprofitable and a waste of time.

This chapter offers a couple of methods for capturing performance data ‚ that is, using the database logoff trigger and PL/SQL procedure. In addition, it is also possible to sample performance data by accessing the SGA directly with an external program. These methods are a good complement to the event 10046 trace facility. The historical data allows the DBA to perform root cause analyses of performance problems.

The ability to monitor all active processes on a 24x7 basis is good. Having repositories to help answer why a particular job ran slowly is great. But having the evidence to prove that the performance problem is not in the database and that you are innocent is PRICELESS! The historical data gives DBAs the evidence they need to confirm or refute the common accusation from developers and business users: ‚“It is a database problem. ‚½




Oracle Wait Interface
Oracle Wait Interface: A Practical Guide to Performance Diagnostics & Tuning (Osborne ORACLE Press Series)
ISBN: 007222729X
EAN: 2147483647
Year: 2004
Pages: 114

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net