VTS (Virtual Table Share)

Optimizing memory resources can be especially challenging when there are different operating environments in a single computing infrastructure.

The optional VTS product allows access to shared, in-memory tables across multiple CICS or IMS regions, from both batch and online environments. VTS allows applications running in different operating environments, (for example batch, TSO/ISPF, CICS TS, or IMS TM), to share data for read and write access.

Loading one copy of data into shared memory reduces I/O, system paging, and overall storage requirements. VTS takes care of memory management and loads tables into memory so that applications and online users may access data from thousands of small tables, or a single table as large as 2 GB.

A VTS-TSR is a shared tableSPACE Region (TSR), and resides in a shared data space (a Local TSR is a private data space). After initiating contact with a VTS-TSR, a calling application can use it as if it were its own local TSR.

Calling application accessing VTS table data
Figure 64. Calling application accessing VTS table data

A VTS-TSR may be called, using standard tableBASE commands, by any programming language that uses the standard IBM calling protocols including C and C++. For more information on VTS, please see the tableBASE Administration Guide.

VTS Application Examples

These are some examples of how tableBASE and VTS are used:

  • Brokerage firms share several common-stock rate tables among applications that run in different regions. Stock information is dynamic, needs to be accessed quickly, and must be maintained in a common data pool. VTS makes this easy to implement by providing instantaneous access to a representation of live data that is shared among all users—a powerful time- and resource-saving opportunity.
  • Service industries with data entry/inquiry systems executing in different IMS TM and/or CICS TS regions share common message tables, and any other tables common to the system. Online decision-support systems operate with the most current data at memory speeds.
  • Banks share money market rates and lender information across several regions and environments. Online and batch applications process orders and transactions faster.
  • Insurance companies share business rules, processing parameters, insurance rates, and customer information for online broker inquiry systems and actuarial or claims processing applications.
  • Retail organizations have shared, in-memory access to store codes, freight tables, inventory lists, and supplier and customer information for online customer inquiry systems, distribution, sales forecasting, and reporting systems.