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Product description

You've got a  problem. The number of datasets you have is growing steadily, but your naming conventions are outmoded and have to be adapted to today's needs. Or you want to integrate another data center into your system and its naming conventions don't match yours.

But changing a dataset name is a lot of work: The dataset has to be renamed in the catalog, the DD statements in the JCL have to be modified, symbolic parms have to be resolved, IMS dynallocs and utilities have to be adapted – and on and on.

Functional Overview

• DSN/Change searches JCL libraries, data cards, CLIST and REXX programs, CA-1 tape management definitions, RACF profiles, IMS dynallocs and more for all references to the files you want to rename. These references are then written to the internal database of DSN/Change. A typical example of a reference is the DSN parameter of a DD statement: DSN=FILENAME.

• DSN/Change creates new file names according to pre-defined rules. These rules are set and maintained by the user in an ISPF dialog. Extensive utilities such as variables, tables and string functions are available.

• DSN/Change simulates all changes. In the so-called TRY mode, old and new file names are listed next to each other and the result you will get after conversion is displayed.

• DSN/Change can reformat DD statements: BLKSIZE, UNIT, VOLUME, MGMTCLAS, DATACLAS, STORCLAS and so forth can be changed, added or removed automatically according to pre-defined rules.

• DSN/Change considers symbolic parameters in the JCL and in procedures.

• DSN/Change compares access rights to old and new dataset names with each other. If they don't match, the differences are displayed.

• DSN/Change renames the physical files (non-VSAM, VSAM, GDGs, IMS databases, tapes) as well as all references to these files while production is running.

• DSN/Change recalls migrated datasets. After renaming, these datasets are returned to the media they were recalled from.

• DSN /Change tracks all modifications: Complete and error-free, no revision is necessary. Such seamless tracking makes it possible to undo all changes at any time.

Example

Here's a simple example to illustrate the basic procedure used for renaming datasets with DSN/Change.

1. Rules are Defined

Rules are used for determining the new file names. In our example, all P390A.DCH.* files are to be renamed P390A.XCP.JOBNAME.* (where JOBNAME is the name of the job creating the files).

2. JCL is Modified

As SMS has now been deployed in our example company, old UNIT, VOLUME and BLKSIZE information is to be removed from the JCL. At the same time, management-class parameters are to be added.

3. Rename is Prepared

The user now selects a group of files to be re-named. Rules are used to create new file names and these names are written to the DSN/Change database. However, the entire conversion should be simulated first in TRY mode. 

4. Results are Verified

In TRY mode, the user can check planned modifications. The old file names are listed next to the new ones and the way the JCL will be modified JCL. 

5.    Files are Renamed

Only now are the files physically renamed or copied. The current batch production does not have to be interrupted: The entire modification process executes automatically in the background:

• The first file is selected for processing.

• If the file has been migrated, it is first "recalled".

• The file is locked (enqueue).

• Only at this point is the file renamed or copied.

• All members with references to the file are changed accordingly.

• The file is unlocked (dequeue) .

•  The next file is processed.

Cost / Benefit Analysis

Empirical values were used for this cost/benefit analysis. Depending on the environment –  the number of symbolic parameters, naming conventions already available, special cases and so on – the benefit may be far higher but, of course, also less than in the example. However, using DSN/Change will always save you a lot of money.

• One man-year costs €75,000.

• Depending on the number of files, DSN/Change costs between €40,000 € and
  €125,000.[1]

• Without DSN/Change an employee can change approximately 10,000 file names per annum using 100% of his or her working time.

• With DSN/Change an employee can rename 50,000 DSNs in 50% of his or her working time. The rest of the time the employee is available for other work.