Application managed text units

The application can manage the dynamic descriptor text units instead of IMS. If the application manages the text units, overhead for parsing and text unit build can be reduced.

Use the SETO call to have IMS build dynamic descriptor text units. After they are built, these text units can be used with subsequent CHNG calls to define the print characteristics for a data set.

To reduce overhead by managing the text units, the text units should be used with several change calls. An example of this is a wait-for-input (WFI) transaction. The same data set attributes can be used for all print data sets. For the first message processed, the application uses the SETO call to build the text units for dynamic descriptors and a subsequent CHNG call with the TXTU= parameter referencing the prebuilt text units. For all subsequent messages, only a CHNG call using the prebuilt text units is necessary.