IBM delivered z/TPFDF default key support for z/TPF support for MongoDB (APAR PJ44378) in April of 2017. This support provides a way for you to access z/TPFDF files that do not have default keys defined in the z/TPFDF database definition (DBDEF).

Previously, the default keys could be defined only in the DBDEFs and doing so was optional. Many DBDEFs do not have default keys defined; instead, the z/TPFDF application uses a DBKEY macro or dfkey() function  to specify the file organization when the application inserts or updates LRECs. With z/TPF support for MongoDB, a z/TPFDF database must have default keys defined. If default keys are not defined, insert, update, and remove requests are rejected.

You might be concerned that adding default key parameters to the DBDEFs for an existing database is risky because it might change the behavior of existing applications. With APAR PJ44378, you can specify default key parameters in the z/TPFDF collection descriptor (adbi.xml files) so that existing DBDEFs do not need to be updated. With this support, MongoDB applications on a distributed system can update z/TPFDF databases that do not have default keys defined in the DBDEF.

For more information about z/TPFDF default key support for z/TPF support for MongoDB, see the APEDIT for PJ44378.