The Catalog Recovery Plus (CR+) product function of
MERGECAT is a very powerful, useful tool to have for the day-to-day management of your BCS environment. Customers use the MERGECAT command to move or copy catalog entries from one BCS to another. Some situations where MERGECAT is useful are:
• A BCS becomes too large and unwieldy, alleviated by moving one or more 'alias groups' of catalog entries to another BCS.
• You determine that you have too many small BCSs, so you consolidate them into fewer, larger BCSs.
• It is necessary to merge catalog entries for 'outside data' brought into existing BCSs in the data center.
• New operating systems are being established and tested, and the BCS COPYONLY facility of MERGECAT is used to set up the new master catalog.
The MERGECAT command is also useful for managing your VOLCAT environment. MERGECAT can be used
to:
• Split specific volume entries from a VGENERAL VOLCAT to a specific (Vx) VOLCAT.
• Merge entries from a specific VOLCAT back into the VGENERAL VOLCAT.
• Copy an entire VOLCAT.
One of the most useful features of MERGECAT is the
MERGECAT WHILE-OPEN option. The user should thoroughly review the
CR+ User's Guide:Chapter 17 prior to utilizing this feature. If you do not have the latest copy of the CR+ User's Guide, you can download it by going to the Rocket Community Portal. There are a set of recommend 'PREP STEPS' that users are encouraged to follow to help ensure the best results from using MERGECAT WHILE-OPEN. These PREP STEPS are as follows:
Recommended Steps To Follow Prior To Executing a MERGECAT WHILE-OPEN job:(1) Ensure that you are completely up-to-date with product maintenance. If you do not know what your maintenance level is, please execute the MCRJMODL job (it's found in the SMCRCNTL library) and send the sysout to the Technical Support team via opening a CASE.
(2) Before attempting to execute a MERGECAT, please thoroughly read the MERGECAT chapter in the User's Guide. Of particular importance are the MERGECAT WHILE-OPEN Usage notes, so please be sure to review those.
(3) Ensure that the catalogs that you are processing (the INBCS and the OUTBCS) are structurally sound via executing an IDCAMS EXAMINE ITEST DTEST against them both. You basically should have the INBCS as error/junk-free as possible before you execute the MERGECAT "for real". Another task that is applicable here is to clean up any orphaned catalog entries in the INBCS via the CR+ DIAGNOSE BCS-VVDS function.
(4) Note that the MERGECAT WHILE-OPEN command requires the presence of the CR+ Started Task,
MCRJMAIN, on all systems in the environment. MCRJMAIN must be "up" (on all systems) before, during, and after the execution of a MERGECAT WHILE-OPEN.
(5) Run your MERGECAT job(s) in
SIMULATE mode first to ensure that it selects the BCS records that you are expecting it to and that the results match what you want.
Review the MERGECAT job output so that you get familiar with MERGECAT's output listing. If you'd like us to review your MERGECAT SIMULATE output, please send us the sysout from your SIMULATE run(s).
(6) It is advisable to run MERGECAT WHILE-OPEN jobs in periods of low activity.
All modes of the CR+ MERGECAT command require the presence of a
journal data set, which is a VSAM KSDS. This is documented in the CR+ User's Guide in the MERGECAT chapter, where the JOURNAL keyword is shown on the syntax diagram to be a required keyword. Each separate MERGECAT job requires it's own unique journal dataset. The journal is used to track the MERGECAT changes so you can restart or back them out if a failure should occur.
If you use the CR+ ISPF panels to generate your MERGECAT jobstream, you can tell it (the panel) to also generate the IDCAMS DEFINE command for your journal data set.
However, below is a sample IDCAMS job step that you can use to create your MERGECAT journal data set within your JCL.
//*your_job_card
//*----------------------------------------------------------------
//* DEFINE THE JOURNAL WORKFILE USED BY THE CR+ MERGECAT FUNCTION.
//*----------------------------------------------------------------
//STEP1 EXEC PGM=IDCAMS,REGION=6M
//SYSPRINT DD SYSOUT=*
//SYSUDUMP DD SYSOUT=*
//AMSDUMP DD SYSOUT=*
//SYSIN DD *
DELETE hlq.your.MERGECAT.JOURNAL PURGE
SET MAXCC = 0
DEFINE CLUSTER( -
NAME(hlq.your.MERGECAT.JOURNAL) -
CYLINDERS(50 50) -
KEYS(65 0) -
RECORDSIZE(32744 32744) -
SPANNED -
) -
DATA( CONTROLINTERVALSIZE(4096) ) -
INDEX( CONTROLINTERVALSIZE(2048) )
/*
Hope you find this useful, and let me know of further questions.
#CatalogRecoveryPlus------------------------------
Anne Bumgarner
Technical Support Engineer
Rocket Software, Inc.
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