Db2 Tools for zOS

Expand all | Collapse all

Information Xchange - A performance question

  • 1.  Information Xchange - A performance question

    Posted Tue October 19, 2021 11:35 AM
    What was your most difficult query performance problem, and how did you solve it?

    ------------------------------
    CALENE JANACEK
    ------------------------------


  • 2.  RE: Information Xchange - A performance question

    Posted Tue October 19, 2021 12:15 PM

    So many that I can't remember a specific one.

    However, for any serious query tuning and performance problem Visual Explain is absolutely VITAL!!!

    So quick and easy to see ALL of the useful information, including query rewrite.

    At one customer I have also used the Virtual Index add on which is also very useful.
    At other customers I have to populate the virtual index DSN tables manually and then perform the explain, maybe this feature could be brought into the no-charge offering?
    I don't mean the full index advisor just a GUI front-end to populate the VI DSN tables.


    Ciao
    Adrian??

    Virus-free. www.avast.com





  • 3.  RE: Information Xchange - A performance question

    Posted Tue October 19, 2021 12:20 PM
    Trying to figure out how to create an XML index in Db2 to improve the performance of SQL queries that access XML data.   Query Workload Tuner is useless in this regard.   This will be a real problem as more people store XML data in Db2.   The only way that I could do this,  was to work directly with the developer to help me come up with the proper XML expression to use in the index.  Even then, it was somewhat hit or miss.

    ------------------------------
    Perry Shindle
    ------------------------------