Improvements to the Wait Interface

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Oracle Database 10g comes with a number of new features that are designed to provide enhanced performance of the Oracle RDBMS. In this chapter we will cover these features, which include

Improvements to the wait interface

The Database Common Management Infrastructure

The SQL Access Advisor

SQL Query tuning enhancements

Automated SGA tuning

Object growth trending

Self-tuning checkpointing

Sorted hash clusters

Oracle 10g offers a number of new and improved database views to assist you in your performance-tuning efforts. The performance-related database views that have been improved through changes include the following:

V$EVENT_NAME

V$SESSION

V$SESSION_WAIT

New views include

V$SESSION_WAIT_HISTORY

V$SESSION_WAIT_CLASS

V$SYSTEM_WAIT_CLASS

Also new in Oracle Database 10g are the histogram views V$EVENT_HISTOGRAM, V$TEMP_HISTOGRAM, and V$FILE_HISTOGRAM. Let's look at each of these in more detail next.

Changes to the V$EVENT_NAME View

The V$EVENT_NAME view has had two new columns added to it that allow you to aggregate wait events based on the type of wait being experienced. The WAIT_CLASS column provides a generalized class type for each event. The WAIT_CLASS# column