ICF Catalog Backup and Recovery: A Practical Guide

102 ICF Catalog Backup and Recovery: A Practical Guide

6.7 MERGECAT command

The Catalog RecoveryPlus MERGECAT command provides functions that are

similar to the IDCAMS REPRO MERGECAT and NOMERGECAT commands. It

either

moves or copies records from one BCS to another, allowing you to merge,

split, or clone BCS records.

In general, the MERGECAT command can be used to move all or some BCS

records to another BCS. Depending on the keywords that you code with this

command, aliases may be changed from the input BCS to the output BCS.

When

not using the COPYONLY keyword, the MERGECAT command performs

as a move function, and therefore, VVDS records for all data sets whose catalog

entry is moved will have a BCS back-pointer update. To achieve maximum

performance in this operation, the BCS back-pointer updates are saved until the

end of processing and are then performed a volume at a time, so that all updates

to each VVDS are done at once. This is unlike the logic in IDCAMS REPRO

MERGECAT, where the VVDS updates are done at the time each record is

moved from the source to the target BCS. This logic is one of the primary factors

in the performance obtained by the CR+ MERGECAT command.

Figure 6-32 illustrates the command used for moving

all

records in a BCS to

another BCS.

Figure 6-32 MERGECAT command to move all BCS records

Every catalog record in UCAT.CRPLUS3 is moved to UCAT.CRPLUS5, and every

alias for UCAT.CRPLUS3 in the master catalog is moved to UCAT.CRPLUS5. At

completion of this command, UCAT.CRPLUS3 is an empty catalog. For every

data set whose catalog record is moved, all the VVDS records (VVRs and NVRs)

change their BCS back-pointer value from UCAT.CRPLUS3 to UCAT.CRPLUS5.

In Figure 6-33, you see the command used to move all records with a high-level

qualifier of YCJRES3, from user catalog UCAT.CRPLUS3 to UCAT.CRPLUS5. By

using the level keyword, the alias YCJRES3 is also changed in the master

catalog from its relationship to UCAT.CRPLUS3 to UCAT.CRPLUS5.

MERGECAT INBCS(UCAT.CRPLUS3) -

OUTBCS(UCAT.CRPLUS5) -

JOURNAL(YCJRES1.MERGECAT.JOURNAL)