Using Stored Outlines

Using Stored Outlines - Now that the outlines have been stored, it is time to use them. Using a stored outline is as simple as setting the USE_STORED_OUTLINES initialization parameter to your category name. To enable this session to use the stored outline already created, issue the following:

ALTER SESSION SET use_stored_outlines=employee_application;
To turn off the use of stored outlines, set the parameter to FALSE:

ALTER SESSION SET use_stored_outlines=FALSE;
When an outline is enabled for your session, the optimizer looks in your category for the SQL statement just issued. If it finds it, then it uses the stored execution plan for that SQL statement. If the category does not contain your SQL statement, the DEFAULT category is examined. If the SQL statement is in the DEFAULT category, that stored outline is used.

It is often helpful to determine if a category is being used. The OUTLINE_CATEGORY column of the V$SQL view will contain the category name if the stored outline is being used for that SQL statement.