DL/I calls for IMS DB system services

Use these DL/I calls to obtain IMS™ DB system services.

Each call description contains:

A syntax diagram
Definitions for parameters that are available to the call
Details on how to use the call in your application program
Restrictions on call usage, where applicable

Each parameter is described as an input parameter or output parameter. “Input” refers to input to IMS from the application program. “Output” refers to output from IMS to the application program.

Syntax diagrams for these calls begin with the function parameter. The call interface (xxxTDLI) and parmcount (if it is required) are not included in the syntax diagrams.

Related reading: For specific information about coding your program in assembler language, C language, COBOL, Pascal, and PL/I, see the topic "Defining Application Program Elements" inIMS Version 13 Application Programming for the complete structure.

System service call summary
The following table summarizes which system service calls you can use in each type of IMS DB application program and the parameters for each call. Optional parameters are enclosed in brackets ([ ]).
APSB call
The Allocate PSB (APSB) calls are used to allocate a PSB for an ODBA application.
CHKP (basic) call
A basic Checkpoint (CHKP) call is used for recovery purposes.
CHKP (symbolic) call
A symbolic Checkpoint (CHKP) call is used for recovery purposes. If you use the symbolic Checkpoint call in your program, you also must use the XRST call.
DPSB call
The DPSB call is used to deallocate IMS DB resources.
GMSG call
A Get Message (GMSG) call is used in an automated operator (AO) application program to retrieve a message from the AO exit routine DFSAOE00.
GSCD call
A Get System Contents Directory (GSCD) call retrieves the address of the IMS system contents directory for batch programs.
ICMD call
An Issue Command (ICMD) call enables an automated operator (AO) application program to issue an IMS command and retrieve the first command response segment.
INIT call
The Initialize (INIT) call allows an application to receive status codes regarding deadlock occurrences and data availability (by checking each DB PCB).
INQY call
The Inquiry (INQY) call is used to request information regarding execution environment, destination type and status, and session status. INQY is valid only for application interfaces that use the AIB structure.
LOG call
The Log (LOG) call is used to send and write information to the IMS system log.
PCB call (CICS online programs only)
The PCB call is used to schedule a PSB call.
RCMD call
A Retrieve Command (RCMD) call enables an automated operator (AO) application program retrieve the second and subsequent command response segments after an ICMD call.
ROLB call
The Roll Back (ROLB) call is used to dynamically back out database changes and return control to your program.
ROLL call
The Roll (ROLL) call is used to abnormally terminate your program and to dynamically back out database changes.
ROLS call
The Roll Back to SETS (ROLS) call is used to back out to a processing point set by a prior SETS or SETU call.
SETS/SETU call
The Set a Backout Point (SETS) call is used to set an intermediate backout point or to cancel all existing backout points.
SNAP call
The SNAP call is used to collect diagnostic information.
STAT call
The Statistics (STAT) call is used in a CICS, IMS online, or batch program to obtain database statistics that might be useful for performance monitoring.
SYNC call
The Synchronization Point (SYNC) call is used to release resources that IMS has locked for the application program.
TERM call (CICS online programs only)
The Terminate (TERM) call is used to terminate a PSB in a CICS online program.
XRST call
The Extended Restart (XRST) call is used to restart your program.

Parent topic: Database management

Related reference:

DL/I calls for IMS TM system services

DL/I calls for transaction management

EXEC DLI commands

IMSCALL command (X'C803')