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Introduction BIM-EPIC Dataset Definitions (EDDs)

1-10 User Reference

is no difference in function between them. You can use both together to group datasets at two

levels. Either one or both can be used for any dataset.

You can cause a specific SYS number to be used for a dataset by entering that SYS number in

the EDD. This inhibits LUB allocation (described in Chapter 7) for the dataset each time it is

processed. We recommend that you avoid assigning a SYS number here unless it is absolutely

necessary. It is better to allow LUB allocation to assign a SYS number for you, or to inhibit

LUB allocation through JCL. If you do assign a SYS number in the EDD, ensure that you do

not use the same number in your JCL for a different dataset in the same job step.

Block size reblocks datasets. It overrides any block size coded in the program’s DTF. If the

block size specified is not a multiple of the record length, BIM-EPIC automatically rounds

down to the closest multiple.

Reblocking is valid only for sequential datasets with fixed or variable record formats, and the

program DTF must already specify a blocked format. It is supported for all datasets processed

by logical IOCS, but may be ignored by programs that use physical IOCS to process the

dataset. It is not valid for tape datasets which are read backward.

Block size and CISIZE are mutually exclusive; you can only specify one of these in a BIM-

EPIC dataset definition.

BIM-EPIC provides four retention criteria: generation or work (described here), and

retention days, cycles retention, and DLA retention (described below). All of them work

together to determine retention for active versions.

The ‘generation or work’ field specifies whether to keep more than one version of the dataset

at a time. When you designate a dataset as a generation dataset, BIM-EPIC maintains at least

the number of versions specified in the cycles retention field. Because each version is also

retained as long as the retention days and DLA retention fields dictate, BIM-EPIC can retain

more versions than the number specified with cycles retention.

When you designate a dataset as a non-generation (or work) dataset, BIM-EPIC retains only

one version of the dataset at a time. As long as no new version is created, that version is

retained as long as the retention days and DLA retention dictate. So, for disk versions, when

you create a new version of a non-generation dataset, the old version is scratched

automatically, whether or not the old version has expired. In addition, entries are

automatically scratched from the VTOC to avoid the “OVERLAP ON UNEXPIRED FILE”

error generated by VSE. For tape versions, the old version is scratched when you execute the

SCRATCH function of the TSIDUTL program.

When you specify a cycles retention of one (1) for a non-generation dataset, BIM-EPIC

always retains one version, even if its other retention criteria have expired.

The retention days field specifies the number of days each version should be retained after its

creation date.

SYS Number

Block Size

Generation or Work

Dataset

Retention Days

1 2 ... 19 20 21 22 23 24 25 26 27 28 29 ... 488 489

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