Question & Answer
Question
An IDCAMS REPRO is used to copy the records from a VSAM data set to a sequential data set, coding the output data set without specifying LRECL and BLKSIZE. There is a false impression that the system should pass the attributes from the input or source data set on to the output or target data set. The REPRO receives IEC141I 013-34 IGG0191I.
Answer
The solution is to code the LRECL and BLKSIZE for the output data set. As stated in the "Using data sets" manual, for an output or target sequential data set, there is no default for the BLKSIZE if it is not specified. For FB, the default for LRECL is BLKSIZE. For VB and VBS, it is BLKSIZE-4.
For example, suppose the maximum record size is 32000. In fact, the records may be much smaller than that (e.g. they may all actually be 264 bytes), but for the moment assume they are all in fact 32000 bytes. The 'Using Data Sets' manual states that the VSAM RDF is not included in the record length. For RECFM=F, an LRECL of at least 32004 would be required to REPRO to a sequential data set. For RECFM=VB, the LRECL would need to be at least 32008. The corresponding BLKSIZE would then need to be either 32008 (RECFM=F) or 32012 (RECFM=VB).
These choices follow the normal rules for creating a SAM data set. Alternately, if it is known that all the records are some length that is actually smaller than 32000 (for example, 2154 is the actual max), then RECFM=VB, LRECL=2162, BLKSIZE=some number greater than 2166 can be specified. This choice is based on the efficiency of blocking on the specific output device.
According to normal SAM rules, if the exact size of the records is not exactly known, using a MAXLRECL of 32000 and a BLKSIZE of 32012 will tell SAM to put as many logical records as it can fit into a block up to 32008 bytes before writing. Some blocks may hold a lot of records, some may hold only one. The point is that normal SAM rules apply for the output data set. Since the LRECLs of the VSAM records to be dumped are usually known (in the worst case, the largest size is known), a BLKSIZE value consistent with SAM that fits the data set specific requirements can be selected.
Related Information
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG90","label":"z\/OS"},"Component":"5695DF106 - DFSMS VSAM","Platform":[{"code":"PF035","label":"z\/OS"}],"Version":"1.1;1.2;1.3;1.4;1.5;1.6;1.7;1.8;1.9;1.10;1.11;1.12;1.13;2.1;2.2;2.3;2.4","Edition":"Enterprise","Line of Business":{"code":"LOB56","label":"Z HW"}}]
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Modified date:
03 September 2021
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