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PH27493: DB2 12 CODE TO SUPPORT NEW FUNCTION FOR UTILITY DATASETS

A fix is available

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APAR status

  • Closed as new function.

Error description

  • Db2 12 code to support new function for utility datasets
    

Local fix

  • n/a
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All Db2 12 for z/OS users.                                   *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * Large number of data sets opened                             *
    * concurrently by Db2 utilities could                          *
    * cause DSMAX to be hit and impact                             *
    * performance of other applications.                           *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Db2 manages its concurrent data set opens against the DSMAX
    limit, dynamically opening and closing datasets as needed in
    LRU fashion to stay within the limit.
    Db2 COPY utility could open a large number of data sets and
    leave the datasets open when the utility completed. That
    could cause DSMAX to be hit and impact the performance of
    other applications.
    

Problem conclusion

Temporary fix

Comments

  • The dataset close processing logic has been improved to
    proactively close datasets that were opened solely for
    utility access.
    Db2 will close utility-only datasets that have not been
    accessed for 10 minutes proactively.
    When approaching DSMAX or DSMAX is reached, Db2 will
    prioritize the closure of utility-only datasets over those
    datasets that have been accessed by applications.
    Two new counters QTPCGBP and QTPCUT are created for the
    IFCID 2 trace records.
    QTPCGBP - Number of infrequently accessed data sets that are
              physically closed.
              A data set is considered to be infrequently
              accessed when it has not been accessed for the
              number of minutes that is specified by system
              parameter PCLOSET.
              Db2 physically closes the infrequently accessed
              data set that is defined with the CLOSE YES option
              when the following conditions occurred in a data
              sharing system:
              o A single member with R/W interest and any number
                members with read-only interest exist.
              o All members have read-only interest and the data
                set has been GBP-dependent since the time it was
                physically opened.
    QTPCUT  - Number of utility-access-only data sets that are
              physically closed.
    Please refer to ++HOLD DOC change for more information.
    ×**** PE21/01/11 FIX IN ERROR. SEE APAR PH33238  FOR DESCRIPTION
    

APAR Information

  • APAR number

    PH27493

  • Reported component name

    DB2 OS/390 & Z/

  • Reported component ID

    5740XYR00

  • Reported release

    C10

  • Status

    CLOSED UR1

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-07-15

  • Closed date

    2020-09-24

  • Last modified date

    2021-02-11

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    UI71764

Modules/Macros

  • DSNTXSTB DSNB1PCP DSNB1DCM DSNB1PFT DSNB1OPP DSNDQTST DSNB1DRN
    DSNB1DS1 DSNB1CPP DSNB5PCI
    

Fix information

  • Fixed component name

    DB2 OS/390 & Z/

  • Fixed component ID

    5740XYR00

Applicable component levels

  • RC10 PSY UI71764

       UP20/10/02 P F010

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Platform":[{"code":"PF054","label":"z\/OS"}],"Version":"12.0"}]

Document Information

Modified date:
12 February 2021