3.9 How and when to perform database maintenance

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When your MVS systems programmer installed WSAA, they — possibly in conjunction with a DB2 DBA — executed a batch job to bind the DB2 packages and plans for the WSAA database. Appendix D, “WSAA installation notes” on page 195 provides you more information about this task. It is important to keep in mind that as you scan production source libraries your WSAA DB2 database experiences significant changes when additions and updates occur.

You, as the WSAA system or product administrator (or your site’s DB2 DBA), must find a way to maintain acceptable database performance for:

  • Ongoing production source library scans

  • Optimal Web browser response time

One way is to invoke the RUNSTATS command on the DB2 database tables.

3.9.1 How to run the WSAA DB2 utilities

To invoke the DB2 housekeeping batch job, do the following:

  1. Log on to your OS/390 or z/OS system.

  2. Go to ISPF Option 6.

  3. Enter the following command, substituting your site’s data set name (or high-level qualifier):

    ex 'wsaa.v2r2.sdmhrexx(dmhinit)'

    The WebSphere Studio Asset Analyzer main menu panel, DMHMAIN, is displayed.

  4. Select Option 3, Utilities. The DMHU000 panel is displayed.

  5. Select Option 2, Submit RUNSTATS. The DMHSBJCL panel is displayed.

    You are given the option of editing the JCL or not.

  6. When you are finished, press the Enter key.

    • If you entered N, to bypass editing the JCL, the batch job is submitted.

    • If you entered Y, to edit the JCL, you are switched to an edit session of the generated JCL where you can modify the job.

    To submit the job, enter the SUBMIT command on the Command line.

  7. Press F3 to return to the WSAA main menu.

  8. Go to SDSF and check that the return code MAXCC is 0.

  9. If there is a nonzero return code, do these steps:

    1. Examine the JESYSMSG output to find “COND CODE” after each step.

    2. Examine the RDPRINT output for detailed results. I-level or W-level messages are acceptable.

    3. If there are errors, make corrections according to the information provided in the error messages, and resubmit the job.

      Note 

      We cannot show you the output of one of these jobs because we are using a database that is shared by a number of other groups and did not have the opportunity (nor the authority) to run this batch job.

3.9.2 When to invoke the DB2 utilities

The DB2 utility RUNSTATS updates the DB2 catalog tables with statistical information about data and indexes. Maintaining these statistics is a critical part of performance tuning: DB2 must have correct statistical information to make the best choices for the access path to the database.

Important:  

We recommend, that as a matter of routine DB2 housekeeping, you invoke the DB2 RUNSTATS and REBIND utility functions:

  • After each CICS region or IMS subsystem is loaded

  • After each partitioned data set it loaded

This will update all of the table indexes and paths so that DB2 can respond more quickly to your Web-based queries.

Now is a great time to make sure you remain friendly with the DB2 DBA who is assigned to work on this project (see 2.3, “Additional support personnel” on page 39). They have the tools and utilities to help monitor the tables and their use.



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IBM Redbooks - Websphere Studio Asset Analyzer
Adobe InDesign CS2 @work: Projects You Can Use on the Job
ISBN: 067232802X
EAN: 2147483647
Year: 2004
Pages: 84

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