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Introduction​

IDCAMS (Integrated Data Set Control Access Method Services) is a utility provided by IBM to manage datasets and catalogs, especially for VSAM and GDG datasets. It allows users to create, delete, define, rename, back up, and list information about both VSAM and non-VSAM datasets. IDCAMS commands are typically used inside JCL or TSO batch jobs to perform catalog-related operations efficiently.

IDCAMS plays a key role in VSAM dataset lifecycle management, GDG operations and is essential for both system programmers and application developers working on IBM Mainframes. Here are some common Knowledge information around IDCAMS.

Some of the most common IDCAMS commands include:

Exercise IDCAMS - DELETE and DEFINE​

  • Create IDCAMS Sysin to define a small KSDS of fixed length record size 80, Key length 8 and CI size 4096.
  • Create IDCAMS SYSIN Delete a VSAM Cluster
  • Delete the previously created KSDS Cluster and Redefine the Same Cluster. It should not fail if previouly defined KSDS does not exists.
  • Define an ESDS dataset with the following properties:
    • Dataset name: YOUR.USER.ESDS
    • Record size: 100 100
    • Space allocation: 10 Track 5 Second Tracks
    • Control Interval Size: 2048
  • Delete a dataset if it exists. If not to terminate further execution of IDCAMS.
  • Reset MAXCC after trying to delete the dataset and delete failed due to non-existing dataset

Exercise - Fix Invalid IDCAMS sysin​

Along with fixing the JCL answer the following

  • What message do you receive in SYSOUT?
  • Does IDCAMS stop processing further commands?
  DEFINE CLUSTER(NAME(MY.DATASET) - 
               KEYS(10 0) -
               RECORDSIZE(80 80)
               TRACKS(5 5))
IF LASTCC = 0 THEN
   DELETE MY.DATASET
END IF
DEFINE CLUSTER(NAME(USER.KSDS) - 
               KEYS(10 0) RECORDSIZE(80 80) -
               TRACKS(5 5))
  DELETE USER.KSDS
  DEFINE CLUSTER(NAME(USER.KSDS) -
                 KEYS(10 0) -
                 RECORSIZE(80 80) - 
                 TRACKS(5 5) )
  LISTCAT LEVEL(USER.KSDS.*) NAME

Exercise: Difference between Define Cluster​

  • Here are the 2 JCLs to allocate KSDS.
//DEFKSDS  EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=*
//SYSIN    DD *
   DEFINE CLUSTER (         -
      NAME(YOUR.USER.KSDS)  -
      INDEXED               -
      TRACKS(1 1)           -
      RECORDSIZE(80,80)     -
      KEYS(8,0)             -
      CISZ(4096))
/*
//CREATEK EXEC PGM=IDCAMS
//SYSIN   DD *
   DEFINE CLUSTER (NAME(YOUR.USER.KSDS1) -
                  INDEXED -
                  KEYS(8 0) -
                  RECORDSIZE(80 80) -
                  TRACKS(1 1)) -
      DATA(NAME(YOUR.USER.KSDS1.D)) -
      INDEX(NAME(YOUR.USER.KSDS1.I))
/*

Questions:

  1. Run LISTCAT job to find out what is the difference details you see for YOUR.USER.KSDS1 and YOUR.USER.KSDS?
  2. What is the CISZ for both the datasets?
  3. Modify the DEFINE CLUSTER command for YOUR.USER.KSDS1 to omit the INDEX portion and observe the result.

Exercise IDCAMS - LISTCAT​

Consider here are some existing 7-8 VSAM datasets

  • CORP.FINANCE.REPORT
  • CORP.SALES.REPORT
  • CORP.SALES.REPORT.MONTHLY
  • CORP.SALES.REPORT.MONTHLY.ARCHIVE
  • CORP.HR.EMPLOYEE
  • CORP.LOGS
  • CORP.TEMP
  • CORP

Find out what entries will be listed for following command.

  • LISTCAT ENTRIES(CORP.*)
  • LISTCAT ENTRIES(CORP.*.REPORT)
  • LISTCAT LEVEL(CORP.SALES.REPORT)
  • LISTCAT LEVEL(CORP.*)
  • LISTCAT ENTRIES(CORP.SALES.*)
  • LISTCAT LEVEL(CORP)
  • Extract the Volume information for all VSAM entries.
  • List all the VSAM cluster Entries(excluding index/data) with matching name
  • Extract the history information of only VSAM Data entry.

Exercise IDCAMS - Print​

  • You are asked to view the content of a KSDS dataset named PROD.CUSTOMERS. Print the data in character format to SYSOUT.
  • Print the contents of an ESDS dataset PAYROLL.RECORDS in DUMP format to a DD name called OUTDD.
  • Print only the first 5 records from an RRDS dataset HR.EMP.RRDS in HEX format.
  • Skip the first 3 records and then print next 4 records from an ESDS dataset LOG.DATA.
  • For KSDS dataset BANK.ACCOUNTS, print all records starting from key 'A100'.
  • Print records in a KSDS dataset ORDERS.FILE between keys '1000' and '2000'.
  • In RRDS EMP.RRDS.DATA, print records from record number 5 to 10.
  • Print records from the start until a specific RBA 00000200 in ESDS ARCHIVE.ESDS.DATA.
  • A user tries to use FROMKEY on an RRDS. What is wrong with this PRINT statement?
  • In KSDS PRODUCT.KSDS.FILE, skip first 2 records and dump rest of the file.

Exercise IDCAMS - REPRO​

  • You have a flat file INPUT.SEQ.FILE with 5 records. Copy it into an empty KSDS named MY.KSDS.DATA.
  • You try to REPRO the same input file again into the KSDS from Exercise 1, without using any special options. What happens?
  • You want to overwrite existing records in a KSDS with new data from a sequential file. Use the REPLACE option.
  • You are REPRO-ing from a sequential file to a KSDS, but you expect some bad records that may fail to insert. Allow REPRO to tolerate up to 2 errors before failing.
  • Copy records from KSDS ORDERS.KSDS with keys in the range '1000' to '2000' only.