Comparing two different versions of the same collection

Use this comparison if you rebind packages regularly and want to gain an understanding of the changes to access plans that result from rebinding.

Procedure

  1. Bind any packages that you want to analyze with the EXPLAIN option set to YES.
  2. Bind the packages to the same collection with the EXPLAIN option set to YES.
    • The packages must be exactly the as they were for the first BIND operation.
    • The application programs that access the packages must not be changed in any way or rebuilt.
    • Ensure that the EXPLAIN output for the BIND operation points to the same set of EXPLAIN tables that you used when binding the packages the first time.
  3. Open the Compare Access Plan Costs window.
    1. In the Data Source Explorer, connect to the subsystem with the two collections.
    2. Expand the connection.
    3. Right-click the subsystem and select Query Tuner > Compare Access Plans.
  4. Select Compare two different versions of the same collection.
  5. Specify the name of the collection and click Add.
  6. Click Generate Report.

What to do next

If the performance of the SQL statements meets your goals, use the rebound packages.

If the performance of any SQL statements regressed, create a query workload with those statements. You can then tune them collectively or individually.


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