A VTS-TSR is a shared tableSPACE Region (TSR), and resides in a shared dataspace. A VTS-TSR allows shared access to tableBASE tables across multiple batch, TSO, CICS TS, DB2 SPAS and IMS TM regions in a single LPAR or z/OS image. Each VTS-TSR has a VTS Agent program which manages the Data Space.

With Version 5 tableBASE VTS-TSRs were read-only. With Version 6 this access was improved to allow full read and write access to tables in a VTS-TSR. With Version 7, VTS Gate features provide added security to manage access to the VTS-TSR; the VTS dataspace can also be initialized as read-only or read-write.

By loading one copy of data into a VTS-TSR, the I/O, system paging, and overall memory requirements can be reduced. A VTS-TSR can be referenced by any programming language that uses the standard IBM calling protocols, including C and C++.

You may have several differently named VTS Agents active simultaneously, allowing you to access multiple shared VTS-TSRs, each of which has a maximum size of approximately 2 GB. (Your installation may impose limits on the number or maximum size of Data Spaces.)

Applications accessing a VTS-TSR may use any mix of batch, TSO, CICS TS, DB2 SPAS or IMS TM interfaces. If a table is opened for write in a VTS-TSR by any user application, it is available for update by any other users of the VTS-TSR unless this is restricted using VTS Gate. The table cannot, however, be opened for write in any other TSR. It is the users’ responsibility to coordinate updates to the table in the VTS-TSR. The LOCK-LATCH capability can also be used as a means to control update access to specific tables in a VTS-TSR.