Lesson 9

This module has served to be a high-level introduction of the major issues in tuning the Oracle SGA.
You should now be able to:

1. Describe the main components of the Oracle SGA
2. Describe the operation of the shared pool
3. Describe the functions of the library cache
4. Query the data dictionary cache
5. List the UGA and session memory considerations
6. Describe how the data buffer cache affects performance
7. Describe the performance issues related to the redo log buffer

Here are some terms used in this module that you may need to review:

1. database buffer cache: An area in memory where Oracle keeps recently used data blocks so that they do not need to be constantly reread from disk.
2. data dictionary cache: The data dictionary cache is used to hold rows from the internal Oracle metadata tables, including SQL stored in packages.
3. dictionary cache miss: Oracle registers a dictionary cache miss when a package is not in memory when it is requested.
4. process memory: The SGA memory allocated on behalf of an Oracle process.
5. redo log buffer: An area in the SGA that Oracle uses to hold redo log entries until they can be written to the log files.
6. session memory: The SGA memory allocated on behalf of an individual Oracle session.
7. SGA: An abbreviation for System Global Area.
8. shared SQL area: The shared SQL area is used to keep and process SQL statements and PL/SQL code.

Before you go on, click the Quiz link below and check your knowledge of the major points in this module.
Oracle Instance Tuning - Quiz
The next module explores specific tuning techniques for the shared pool.