IBM Information Management System (IMS)

  • 1.  What type of IMS Database is this ?

    Posted Wed May 04, 2022 08:16 AM

    Hi All ,

    I am new to IMS and working on a undocumented IMS DB system .
    I have been asked to perform segment size change of a some database . Lets say segment name is COURSE. 
    Now when I check COURSE segment in my DBD lib dataset it is present in 6 DBD source members .
    lets say 
    DI02CP01
    DI02CP02
    DI02CP03
    DI02CP04
    DI02CP05
    DI02CP06

    When I do display database /dis db all I see all these (above) dbd's are open and allocated. So I need to make change in all 6 source members and do dbdgen.

    When I compared dbd source statements with one another  the source definition is same all segments same except for dbname and  ddname 
    DBD NAME=DI02CP01                       DBD NAME=DI02CP02
    DSG001 DATASET DD1=DI02CP1C --- DSG001 DATASET DD1=DI02CP2C
    Each dd has its own dataset .

    Database type is HDAM and access is OSAM.

    While on call with application support team they mentioned these are all partitions of one database .
    My confusion is if partition it should say partition somewhere in DBD source or in DBRC . Which I am not able to find. 
    Want to know what type of database is this HDAM , PHDAM ?  

    Could you please help me in understanding this ?

    Regards,
    Manoj K Jadwani










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    Manoj Jadwani
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  • 2.  RE: What type of IMS Database is this ?

    Posted Wed October 26, 2022 04:58 PM
    Hi Manoj,

    Please accept my sincere apologies.  I noticed that we have not answered your post in a few months.  Sorry about that.
    Its quite possible that the database is partitioned but the partitioning is being done by the application and not IMS.
    When IMS maintains the partitioning, that database is a called a HALDB database.  But HALDB databases were introduced back in IMS V7.
    So for a very old database that was created before HDAM, , I suspect the partitioning is being maintained by the application code.
    For a HALDB HDAM database it will say PHDAM in the DBD statement.
    If you have further questions, just email me directly at deepakk@us.ibm.com.
    Again, sorry for the late response.
    Deepak Kohli

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    DEEPAK KOHLI
    IMS Offering Manager
    IBM
    CA
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    Original Message