When a table is identified for updating in a region with the use of the Open for Write command (OW), steps are taken to prevent other MVS tasks on the same or other MVS images from updating the same table. This is achieved by issuing an enqueue request. The enqueue minor name includes the Table Name and Table Library Dataset Name. The enqueue major name is TBLBASE. The scope of the enqueue is SYSTEMS.
An installation’s modifications to Global Resource Serialization (GRS) PARMLIB controls must not prevent the propagation of the major enqueue name throughout the complex. Failure to adhere to this can result in the corruption of the tableBASE libraries on DASD shared between several MVS images running tableBASE.
Since these requirements are beyond the scope of tableBASE software, you must ensure that these conditions are met if the same tableBASE libraries are to be shared between MVS tasks.