Statistics Collection
Statistics about the operation of an Oracle database are kept in the dynamic V$ data dictionary views (described in Chapter 6). Because the information in these dynamic views is lost when an instance is stopped, Oracle provides packages for saving the performance statistics gathered for these views.
Prior to Oracle8i, the UTLBSTAT and UTLESTAT scripts were used for this purpose. With Oracle8i, the Statspack package was introduced as an improvement on UTLBSTAT and UTLESTAT.
Tip
In addition to these packages, you can use Oracle Enterprise Manager and its Diagnostic Pack add-on for monitoring performance-related statistics. See Chapter 16.
Collecting statistics is the first step to understanding performance problems. It is beyond the scope of this book to help you to learn the delicate art of performance tuning, but there are many fine books on the topic.