SQL Optimizer for Oracle 9.3.1 - User Guide

Tutorial: Best Practices

You can use Best Practices to analyze your SQL statement and database to recommend common techniques for improving database performance. Since the recommendations can also affect performance of other statements in your database, you should review and test the recommendations before implementing them. When evaluating the recommendations, take into account that database performance is affected by the following:

• System resources (CPU, I/O, memory, database architecture, and more)

• Data distribution

• System architecture

• SQL execution plans

• User's usage behavior

Note: The Best Practices function is only available in SQL Rewrite mode in Optimize SQL.

To view best practices

1. Select the Optimize SQL tab in the main window.

2. Click .

   Tip: To display the best practices tab, click , select Optimize SQL | Best Practices | General, and select the Display Best Practices tab in SQL Rewrite mode checkbox.

3. Enter a SQL statement into the Alternative Details pane.

4. Click . The Select Connection and Schema window displays.

5. Select a connection and schema to use.

6. Review the recommendations provided.

Tutorial: Deploy Outlines

The Deploy Outline function in Optimize SQL improves SQL statement performance without changing your original source code. Using Optimize SQL, you can generate SQL statements that are semantically equivalent to your original SQL statement with alternative execution plans. Once you identify the best alternative for your database environment, you can deploy it as a stored outline to use with your original statement.

To deploy an outline

1. Select the Optimize SQL tab in the main window.

2. Click the arrow beside and select New SQL Rewrite Session.

3. Enter your original SQL statement in the Alternative Details pane and click . The Select Connection and Schema window displays.

4. Select a connection and schema to use.

5. Right-click the alternative you want to deploy as an outline in the Alternatives pane and select Deploy Outline. The Deploy Outline window displays.

6. Review the following for additional information:

   Outline name	Enter a name for the stored outline
   Category	Click and select a previously created category or enter a new category name. Notes: The default category name is SQL_OPTIMIZIER. You can add the outline to a disabled category until you test the SQL statement with and without using the outline.

7. Click .

Note: You can use the Outline Management feature in Manage Plans to enable and disable categories or to move outlines to different categories.

Tutorial: Batch Optimize SQL

To batch optimize SQL

1. Select the Batch Optimize tab in the main window.

2. Click Add Code to Optimize in the Batch Job List pane and select All Types. The Add Batch Optimize Jobs window displays.

3. Review the following for additional information:

   Connection Page	Description
   Connection	Click to select a previously created database connection. Tips: Click to open the Connection Manager to create a new connection. You can select an alternative connection for executing the SQL statement alternatives Batch Optimize generates.
   Database Objects Page	Description
   Database objects	Select a schema, database object type, or individual database object, and then click to add the object. Tip: Click to browse for database objects. Your database privileges determine if you can scan all selected database objects.
   Execute using schema	Click and select an alternative schema for executing the SQL statement alternatives.
   Source Code Page	Description
   Source code type	Select Text/Binary files, Oracle SQL *Plus Script, or COBOL programming source code to indicate the source code type for the file or directory you want to scan.
   Add by file	Click and browse to the files you want to add.
   Add by directory	Click and browse to the directories you want to add. Note: Select the Include Sub-directory checkbox to scan sub-directories.
   Scan using schema	Click and select a schema to scan.
   Execute using schema	Click and select an alternative schema for executing the SQL statement alternatives.
   SQL Text Page	Description
   SQL text	Enter SQL statement text.
   Scan using schema	Click and select a schema to scan.
   Execute using schema	Click and select an alternative schema for executing the SQL statement alternatives.
   Scan SQL Page	Description
   Group	Select the Scanner group that contains the SQL statements you want to scan.
   Scan using schema	Click and select a schema to scan.
   Execute using schema	Click and select an alternative schema for executing the SQL statement alternatives.
   Inspect SGA Page	Description
   Group	Select the Inspector group that contains the SQL statements you want to scan.
   Scan using schema	Click and select a schema to scan.
   Execute using schema	Click and select an alternative schema for executing the SQL statement alternatives.
   Note: Batch Optimize helps you manage jobs by organizing them into batches. Use the Batch Info page to create a new batch or to add the current job to an existing batch.

4. Click Finish to start batch optimization.

   Batch Optimize scans the job you created, classifies and optimizes the statements, and executes the SQL statement alternatives it generates.

   Notes: 

   • Scanning starts automatically if you select the Automatically start extracting SQL when job is added checkbox in the Batch Optimize options page. Batch Optimize selects this checkbox by default.

   • Batch Optimize selects the SQL statement to optimize based on the classification types selected in the Batch Optimize options page. Batch Optimize selects Problematic and Complex SQL classification types by default.

   • Batch Optimize executes SQL alternatives it generates based on the statement types selected in the Batch Optimize options page. Batch Optimize selects SELECT statements by default.

5. Select Batch List in the Batch Job List pane to view information about the jobs you created.

   The Batch List pane sorts information about your jobs by batches. Additional information displays in the Jobs Improved pane.

6. Select a batch from the batch list node to see details for the batch in the Job List pane.

   The Job List pane displays the type of job, job status, and time of improvement for each job in the batch. Additional information displays in the SQL Classification and Cost and Elapsed Time Comparison panes for a selected job.

   Tip: Select a job in the Job List pane and click to generate a replacement script with the optimized SQL statement.

7. Select a job from the batch node to see details of the job.

   The SQL List pane displays SQL classification information for the SQL statements in the job you select. The Original SQL Text and Best Alternative SQL Text panes allow you to compare your original SQL statement with the best alternative Batch Optimize generated.

   Tip: Select a SQL statement in the SQL List pane and click to send the statement to Optimize SQL and view all SQL alternatives.

Tutorial: Scan SQL

Scan SQL helps you identify problematic SQL statements in your database environment by automatically extracting statements embedded in database objects, stored in application source code and binary files, or captured from Oracle's System Global Area. Scan SQL retrieves and analyzes execution plans for the extracted statements and classifies them according to complexity. You can then send statements that Scan SQL classifies as problematic or complex to Optimize SQL.

Note: This topic focuses on information that may be unfamiliar to you. It does not include all step and field descriptions.

To scan SQL

1. Select the Scan SQL tab in the main window.

2. Click to select a previously created group or click to create a new group for your scan job.

   Note: Scan SQL helps you manage scan jobs by organizing them into groups.

3. Click . The Add Scanner Jobs window displays.

4. Review the following for additional information:

   Page	Description
   Database Objects Page
   Database objects	Select a schema, database object type, or individual database object, and then click to add the object. Tip: Click to browse for database objects.
   Source Code Page
   Source code type	Select Text/Binary files, Oracle SQL *Plus Script, or COBOL programming source code to indicate the source code type for the file or directory you want to scan.
   Add by file	Click and browse to the files you want to add.
   Add by directory	Click and browse to the directories you want to add. Note: Select the Include Sub-directory checkbox to scan sub-directories.
   Scan using schema	Click and select a schema to scan.
   Inspect SGA Page
   Group	Select the Inspector group that contains the SQL statements you want to scan.
   Scan using schema	Click and select a schema to scan.

5. Click Finish to start scanning.

6. Select a scan job from the Job List pane to view additional information.

   Details displayed in the Job List pane include the number of SQL statements found and the classification for each statement.

   Tip: Click and select a different group to display scan jobs from a different group.

7. Select a SQL statement in the SQL List pane to view additional information for the selected statement in the SQL Text and Execution Plan panes.

   Tip: Click in the SQL Text pane to send the selected statement to Optimize SQL.