The Access Path Advisor examines
the access plan that is chosen by the optimizer and identifies certain
common access path issues. The warnings that this advisor provides
can help you to understand where to look for trouble in an access
plan graph or in the Access Plan Explorer.
About this task
The recommendations of the Access Path Advisor appear in
the Access Path section of the Review Single-Query Advisor Recommendations
page. The following steps are a guide to using this section to follow
the recommendations.
Procedure
To generate recommendations for changing the access path
of an SQL statement:
- After running the DDL scripts that were
recommended by the Index Advisor, return to the Run Single-Query
Advisors and Tools page of the Invoke section in the workflow
assistant. Click the Invoke tab
on the left side of the workflow assistant. If the Run Single-Query
Advisors and Tools page is not open, click Run
Advisors and Analysis Tools on the left side of the workflow
assistant to open the page.
- Click the Select What
to Run button.
- In the Select Activities window, select the Access
path check box. Then, click OK. After the Access Path Advisor runs, the Review
Advisor Recommendations page of the Review section
opens. The Summary section shows whether there
are any recommendations for revising the access path.
- In the Review Single-Query Advisor Recommendations page,
double-click the Access path row in the Summary table.
If this advisor has more than one recommendation, a row appears for
each recommendation.
- In the Access Path section, view
the underlined portion of the SQL statement. The recommendation refers
to the underlined portion.
- Read the details of the recommendation, an explanation
of the best practice behind the recommendation, and, if provided,
an example of an implementation of the recommendation.
- Follow the instructions that the advisor gives for resolving
the problem that led to the recommendation.
What to do next
Run the Query Advisor, if you have not already done so, and
then run the Index Advisor.