GSAM coding considerations

The calls your program uses to access GSAM databases are not the same as the DL/I calls. The system service calls that you use with GSAM are symbolic CHKP and XRST.

The following table summarizes GSAM database calls. The five calls you can use to process GSAM databases are:

  • CLSE
  • GN
  • GU
  • ISRT
  • OPEN

The COBOL, PL/I, Pascal, C, and assembler language call formats and parameters for these calls are the same and are described in the following table. GSAM calls do not differ significantly from DL/I calls, but GSAM calls must reference the GSAM PCB, and they do not use SSAs.

Java™ application programs running in Java batch processing (JBP) regions can access GSAM databases by using the IMS Java dependent region resource adapter.

Table 1. Summary of GSAM calls
Call Formats Meaning Use Options Parameters
CLSE Close Explicitly closes GSAM database None function, gsam pcb
GNbb Get Next Retrieves next sequential record Can supply address for RSA to be returned function, gsam pcb, i/o area [,rsa name]
GUbb Get Unique Establishes position in database or retrieves a unique record None function, gsam pcb, i/o area, rsa name
ISRT Insert Adds new record at end of database Can supply address for RSA to be returned function, gsam pcb, i/o area [,rsa name]
OPEN Open Explicitly opens GSAM database Can specify printer or punch control characters function, gsam pcb [, open option]