Verify the Correctness of Rewritten SQL
Verify the correctness of the rewritten SQL statement by comparing it with the original SQL statement. Use the Run Result function and the Records Returned column of the Run Time pane. This information enables you to see whether the optimized SQL statement provides the same results as the original SQL statement.
Note: The Run Result function is not available for index-set alternatives listed in the Run Time pane.
Run Result
The Run Result function retrieves the queried records from the connected database.
Records Returned
The Records Returned columns display the number of records influenced by the SQL statement. The figure should remain constant for both the original and optimized SQL statements.
Test for Scalability
You can test a single SQL or index-set alternative to find out how it will perform under different amounts of data in your database in Quest's Benchmark Factory program (version 4.6 or later).
To send SQL statement to Benchmark Factory
-
Click
to optimize the original SQL statement. The rewritten SQL versions display as alternatives in the Run Time pane..
- Click
to generate virtual index sets and add them as alternatives.
-
Click Test for Scalability
.
- Select the alternative you want to test.
Create Benchmark Factory Import File
All the SQL statements can be saved in a text file from the Job Manager, the Scanned SQL Viewer, the SQL Repository, and the SQL Optimizer windows. These SQL statements can then be imported into Benchmark Factory program (version 4.6 or later).
To create the text file to import into Benchmark Factory
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Right-click and select Create Benchmark Factory Import File.
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Select the specific SQL statements that you want to save. Click OK.
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Enter the filename and select the file location. Click Save.
Batch Run
Quest SQL Optimizer for IBM® DB2® LUWmaximizes SQL performance by automating the manual, time-intensive and uncertain process of ensuring that SQL statements are performing as fast as possible. SQL Optimizer analyzes, rewrites, and evaluates SQL statements within multiple database objects, files, or SQL statements captured by the DB2 Event Monitor. With SQL Optimizer, you can analyze and optimize all your problem SQL from multiple sources. SQL Optimizer also provides you a complete index optimization and plan change analysis solution, from index recommendations to simulated index impact analysis, through comparison of multiple SQL access plans.
SQL Optimizer provides you with the following main modules.
SQL Optimizer (including SQL Rewrite and Generate Indexes functions)