Control statements for the Image Copy function (DFSUDMP0 JCL)

The control statements for the Image Copy function that is invoked through IMS compatible JCL must reside in the SYSIN data set.

The utility control statement for the Image Copy function using IMS compatible JCL uses a fixed format as shown in the following figure:

This figure shows the format of the utility control statement for using IMS compatible JCL.

Notes:

You must not specify the SYSIN control statement if you are using the FABJMAIN program.
The position after column 38 changes after the Image Copy function processing.

Position

Description

1

The field ID

Specify the character D, which identifies the statement as an IMS HP Image Copy control statement.

2

Number of copies

Specify 1 or 2, depending on the number of copies required.

3

Blank or character I

If I is coded, an image copy of index of KSDS is requested, and position 13 must be the KSDS ddname. The I option is not applicable for OSAM data sets. If position 3 is blank, and if position 13 specifies the ddname for the KSDS, an image copy of the KSDS is produced.

Image copy and recovery of an embedded index of a KSDS are not possible. However, a normal full recovery of the KSDS rebuilds an embedded index and the KSDS data area.

4-11

DBD name

Specify the name of the physical DBD that includes the name of the data set to be dumped.

13-20

INPUT DD name

Specify the ddname of the input data set or area name to be dumped. The name must appear in the DBD, and a corresponding DD statement must be provided.

22-29

OUTPUT DD name

Specify the ddname of the primary output data set. A corresponding DD statement must be provided.

31-38

COPY DD name

Specify the ddname of the second copy of the dumped data set. This field must be blank if position 2 contains a 1. If present, a corresponding DD statement must be provided.

39

A blank, or the character Y or N

If the compression exit is used, specify Y. If not, Specify N or a blank.

40-47

If position 39 is Y, this position must contain the compression routine name. If position 39 is Y and this position contains all blanks, FABJCMP1 is used as the default. If position 39 is N or a blank, this position is ignored. For more information, see Compression routines.

The following specifications are used only for the HASH Check option. If you do not want to invoke this function, you can place comments in positions 48 - 80; in this case, the character on column 48 must not be Y.

48: Blank, the character Y, or any
If you want to invoke the HASH Check option, you must specify Y. If you specify any other character or a blank, positions 48 - 80 are regarded as comment.
49: Character # or any
If you want to evaluate SSP pointers in DEDB, you must specify #.
50-80: Comments can be placed in positions 50 - 80.

Compression routines

IMS HP Image Copy provides four compression exit routines: FABJCMP1, FABJCMP2, FABJCMP3, and FABJCMP4. Specify one of these compression routines to be called by FABJDMPx. If the compression routine name is not specified in the utility control statement (that is, position 39 is Y and position 40-47 is blank), FABJCMP1 is used as the default. The same compression routine is automatically called by FABJRDMx to decompress the compressed data.

FABJCMP1: Runs repeating-characters compression. Free space might also be compressed.
FABJCMP2: Runs free-space compression. The segment data is not compressed.
FABJCMP3: Runs repeating-characters compression of the z/OS® program compression method. Free space might also be compressed.
FABJCMP4: Runs z/OS program compression of the z/OS. Both segments and free space are compressed without distinction.

Important: If the database is a DEDB that has SDEP segments, use FABJCMP4. Other compression routines might damage the SDEP segments.

Selecting whether to compress your image copies and which compression routine to use depends on the following factors of your installation:

The amount of CPU time available
The compression ratio allowable

Generally, FABJCMP1, FABJCMP3, and FABJCMP4 use more CPU time than FABJCMP2, but FABJCMP3 achieves better compression and uses less CPU time than FABJCMP1. FABJCMP4 uses less CPU time than FABJCMP3, but FABJCMP3 achieves better compression than FABJCMP4.