16.20 - Maximum-parcel and Large-row-OK Options - Teradata Tools and Utilities

Teradata® Call-Level Interface Version 2 Reference for Mainframe-Attached Systems

Teradata Tools and Utilities
September 2019
Programming Reference

Newer databases are being defined with fields or rows greater than 32767 bytes; as a result, applications will need to support larger response and parcel sizes. Therefore, set the Maximum-parcel option to H and the Large-row-OK option to 'Y' for all future applications to indicate that the application can support parcel sizes greater than 32767 bytes.

The logic of the application is not affected, only certain uses of signed two-byte unsigned integers. Because values greater than 32767 exceed the capacity of such integers on IBM mainframes, applications must insure that any value that is based on parcel length must use longer integers or unsigned integers. If this is not done, CLIv2 could return a length that could be considered to be a negative value, with unpredictable results.

Since the maximum value that can be contained in the two-byte length is 65535, requests with larger lengths cannot use Varying-length-request. Responses with Varying-length-fetch that require larger lengths will be rejected.

Because PL/I does not support unsigned integers, you cannot use the Varying-length-request option to allow the PL/I VARYING attribute for the Request-pointer or the USING-data-pointer for requests greater than 32767. This same consideration also applies to use of the Varying-length-fetch option and the Fetch-data-pointer.

When using Move Mode, you may need to increase the Fetch-maximum-data-length to accommodate the larger parcels.