CICS VSAM Transparency for z/OS, Version 1.2


Generating records for multiple secondary table records

In MULTIRD, each VSAM record was split between the primary table and one of four secondary tables. You may want to split a single VSAM record into several different DB2® tables.

To illustrate this, assume that you want to split each VSAM record into one primary table and three different secondary tables. CICS® VT handles the data in the primary table. Your IRD is responsible for processing the data in the three secondary tables. The main consideration is handling the initial data migration.

The VIDLOAD utility creates fixed length output records. You specify the length of the output record in IRDB2DLN. This is described in Initial data migration. To migrate a VSAM record to three secondary tables, set IRDB2DLN to the length of the longest of the three DB2 records. Pad shorter records with spaces.

IRDTYPE cannot be used to distinguish different record types in this situation. Your IRD must build record identifier fields. For example, assume that the working storage area your IRD builds that contains the data for the secondary tables is as follows:
+-+---+--------+-----+-+---+--------------+-+---+----------+---+
|X|key| T1 data| pad |Y|key|T2 data       |Z|key| T3 data  |pad|
+-+---+--------+-----+-+---+--------------+-+---+----------+---+
This shows the area addressed by IRDB2DAT. The data for the first table (T1) has a record identifier of X. The data for the second table (T2) has a record identifier of Y and the data for the third table (T3) has a record identifier of Z. The T2 table has the longest row, so the value your IRD sets in IRDB2DLN is T2 row length plus the length of the record identifier. The data for tables T1 and T3 are padded to the length of T2.

In this situation, always set IRDTYPE=??.

The DB2 load cards for the table T1 should include WHEN(1:n) = ‘X', and the equivalent values for loading tables T2 and T3.



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Last updated: December 6, 2013 20:44:59

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Timestamp icon Last updated: Friday, 6 December 2013


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