Figure 5-18. Many factors-such as cost, maintenance, security, the end users' experience and location, and computing system capacity-helped push Oracle to embrace a web-based architecture. This is a highly simplified drawing highlighting the key Oracle architectural components: browser, Oracle client process, Oracle server process, and the Oracle SGA.

Conceptually, all database activity flows through DBMS_MONITOR, and if any activity meets certain specific criteria, the activity is captured. So instead of focusing on a specific user (which you can do), you focus on defining the criteria of interest. Oracle introduced DBMS_MONITOR in Oracle Database 10g, and unlike other diagnostic features, it does not require an additional license.

This package combines many of the ways we have traditionally traced Oracle processes, but extends it to meet modern architecture challenges. DBMS_MONITOR allows for the creation of trace files, including bind variables, SQL, and wait event details. Additionally, it collects v$sesstat and v$sess_time_model-based statistics. DBMS_MONITOR is a very flexible and nicely designed package that eventually every DBA will use.