The primary purpose of your Oracle database is to provide a way to store information for future retrieval. Oracle has several mechanisms that will improve the performance of data retrieval
The optimizer determines the most efficient way to execute a SQL statement after considering many factors related to the objects referenced and the conditions specified in the query.
This determination is an important step in the processing of any SQL statement and can greatly affect execution time.
A SQL statement can be executed in many different ways, including the following:
- Full table scans
- Index scans
- Nested loops
- Hash joins
In this module, you will learn how to:
- Describe the Oracle optimizers functions
- Describe optimizer features of Oracle
- Use stored outlines to predetermine optimizer behavior
- Describe the components and uses of the
DBMS_STATS to collect and move statistics
- Describe the tools available for monitoring database operations
- Use Oracle Enterprise Manager to monitor database activity
The optimizer and query utilities in Oracle will help you improve the performance of your user queries and in many cases, transparently.