A MAP table is a TIBCO Object Service Broker analog of a C or PL/I structure, an assembler language DSECT, or COBOL file definition. Using the Table Definer, you can define a MAP table so that its fields map an area of main storage. External data can be in various storage locations such as: CICS COMMAREA, IMS SPA, or COBOL structure.
Each field has an offset associated with it. The offset allows an external data type to begin on any byte boundary and possibly to overlap the other fields in the same table definition.
You use the Table Definer to define a MAP table. A pointer to the storage area is provided by the external environment or program that calls TIBCO Object Service Broker. TIBCO Object Service Broker itself also provides facilities for allocating storage of several classes for use with MAP tables. Pointers to these areas can in turn be passed to external programs called by TIBCO Object Service Broker.
Both external and internal (TIBCO Object Service Broker) data formats can be specified. Since not all external data formats exactly match a TIBCO Object Service Broker data format, conversion is provided between internal and external formats as required.
MAP tables are intended for use by experienced developers who are thoroughly familiar with both TIBCO Object Service Broker and the environment where their application executes. Incorrect or careless use of MAP tables could cause errors or data corruption that extends beyond the application using these tables. Therefore, TIBCO Object Service Broker provides restrictive default security controls for MAP table use.
These controls should be overridden only to the extent necessary and all MAP table applications should be carefully reviewed to ensure their correctness.