Lesson 4 | The EXPLAIN PLAN utility |
Objective | Run an EXPLAIN PLAN statement. |
Oracle EXPLAIN PLAN Utility
Creating Path Information
- We create the PLAN TABLE by running the utlxplan.sql script,
- Once the PLAN TABLE has been created, we must populate it with access path information.
- At this point, the SQL optimizer has only been directed to compute the access place and place it in the PLAN TABLE.
- The EXPLAIN PLAN output, if read correctly, reveals vital information.
Create Plan Table
Now that we have a broader understating of how to use the EXPLAIN PLAN, let us try out our new skills by seeing how to detect full-table scans.
Reading Oracle Plan Table
Before moving on to the next lesson, click the Exercise link to try your hand at creating a PLAN table and analyzing an output.
Reading Oracle Plan Table