DL/I call functions

The following table shows the DL/I call functions supported in DFSDDLT0 and which ones require data statements.

Table 1. DL/I call functions
Call	AIB Support	PCB Support	Data Stmt ¹	Description
CHKP	yes	yes	R	Checkpoint.
CHNG	yes	yes	R	Change alternate PCB.
CHNG	yes	yes	R	Contains the alternate PCB name option statement and feedback statement optional.
CMD	yes	yes	R	Issue IMS™ command. This call defaults to I/O PCB.
DEQ	yes	yes	R	Dequeue segments locked with the Q command code. For full function, this call defaults to the I/O PCB, provided a DATA statement containing the class to dequeue immediately follows the call. For Fast Path, the call is issued against a DEDB PCB. Do not include a DATA statement immediately following the DEQ call.
DLET	yes	yes	O	Delete. If the data statement is present, it is used. If not, the call uses the data from the previous Get Hold Unique (GHU).
FLD	yes	yes	R	Field—for Fast Path MSDB calls using FSAs. This call references MSDBs only. If there is more than one FSA, put a nonblank character in column 34, and put the next FSA in columns 16-34 of the next statement. A DATA statement containing FSA is required.
GCMD	yes	yes	N	Get command response. This call defaults to I/O PCB.
GHN	yes	yes	O²	Get Hold Next.
GHNP	yes	yes	O²	Get Hold Next in Parent.
GHU	yes	yes	O²	Get Hold Unique.
GMSG³	yes	no	R	Get Message is used in an automated operator (AO) application program to retrieve a message from AO exit routine DFSAOE00. The DATA statement is required to allow for area in which to return data. The area must be large enough to hold this returned data.
GN	yes	yes	O²	Get Next segment.
GNP	yes	yes	O²	Get Next in Parent.
GU	yes	yes	O²	Get Unique segment.
GUR	yes	no	R	Get Unique Record from the IMS catalog database. Tip: Specify LCASE=C on the OPTION statement to make the records, which are returned as XML instance documents, more readable.
ICAL	yes	no	R	IMS Call enables an application program that runs in the IMS TM environment to send a synchronous request for data or services to a non-IMS application program or service that runs in a z/OS® or distributed environment.
ICMD³	yes	no	R	Issue Command enables an automated operator (AO) application program to issue an IMS command and retrieve the first command response segment. The DATA statement is required to contain the input command and to allow for area in which to return data. The area must be large enough to hold this returned data.
INIT	yes	yes	R	Initialization This call defaults to I/O PCB. A DATA statement is required. Use the LLZZ format.
INQY³	yes	no	R	Request environment information using the AIB and the ENVIRON subfunction. The DATA statement is required to allow for area in which to return data. The area must be large enough to hold this returned data.
INQY³	yes	no	R	Request database information using the AIB and the DBQUERY subfunction, which is equivalent to the INIT DBQUERY call. The DATA statement is required to allow for area in which to return data. The area must be large enough to hold this returned data.
ISRT	yes	yes		Insert.
			R	DB PCB, DATA statement required.
			O	I/O PCB using I/O area with MOD name, if any, in columns 16-23.
			R	Alt PCB.
LOG	yes	yes	R	Log system request. This call defaults to I/O PCB. DATA statement is required and can be specified in one of two ways.
POS	yes	yes	N	Position - for DEDBs to determine a segment location. This call references DEDBs only.
PURG	yes	yes		Purge.
			R	This call defaults to use I/O PCB. If column 16 is not blank, MOD (message output descriptor) name is used and a DATA statement is required.
			O	If column 16 is blank, the DATA statement is optional.
RCMD³	yes	no	R	Retrieve Command enables an automated operator (AO) application program to retrieve the second and subsequent command response segments after an ICMD call. The DATA statement is required to allow for area in which to return data. The area must be large enough to hold this returned data.
REPL	yes	yes	R	Replace—This call references DB PCBs only. The DATA statement is required.
RLSE	yes	yes	N	Release all locks held by an application that are for unmodified data.
ROLB	yes	yes	O	Roll Back call.
ROLL	no	yes	O	Roll Back call and issue U778 abend.
ROLS	yes	yes	O	Back out updates and issue 3303 abend. Uses the I/O PCB. Can be used with the SETS call function. To issue a ROLS with an I/O area and token as the fourth parameter, specify the 4-byte token in column 16 of the CALL statement. Leaving columns 16-19 blank will cause the call to be made without the I/O area and the token. (To issue a ROLS using the current DB PCB, use ROLX.)
ROLX	yes	yes	O	Roll call against the DB PCB (DFSDDLT0 call function). This call is used to request a Roll Back call to DB PCB, and is changed to ROLS call when making the DL/I call.
SETO	yes	yes	N	Set options. OPTION statement required. FEEDBACK statement optional.
SETS/SETU	yes	yes	O	Create or cancel intermediate backout points. Uses I/O PCB. To issue a SETS with an I/O area and token as the fourth parameter, specify the four-byte token in column 16 of the CALL statement and include a DATA statement. Leaving columns 16-19 blank will cause the call to be made without the I/O area and the token.
SNAP⁴	yes	yes	O	Sets the identification and destination for snap dumps. If a SNAP call is issued without a CALL DATA statement, a snap of the I/O buffer pools and control blocks will be taken and sent to LOG if online and to PRINTDD DCB if batch. The SNAP ID will default to SNAPxxxx where xxxx starts at 0000 and is incremented by 1 for every SNAP call without a DATA statement. The SNAP options default to YYYN. If a CALL DATA statement is used, columns 16-23 specify the SNAP destination, columns 24-31 specify the SNAP identification, and columns 32-35 specify the SNAP options. SNAP options are coded using ‘Y' to request a snap dump and ‘N' to prevent it. Column 32 snaps the I/O buffer pools, columns 33 and 34 snap the IMS control blocks and column 35 snaps the entire region. The SNAP call function is only supported for full-function database PCB.
STAT⁵	yes	yes	O	The STAT call retrieves statistics on the IMS system. This call must reference only full-function DB PCBs. Statistics type is coded in columns 16-19 of the CALL FUNCTION statement. DBAS For OSAM database buffer pool statistics. VBAS For VSAM database subpool statistics. Statistics format is coded in column 20 of the CALL FUNCTION statement. F For the full statistics to be formatted if F is specified, the I/O area must be at least 360 bytes. U For the full statistics to be unformatted if U is specified, the I/O area must be at least 72 bytes. S For a summary of the statistics to be formatted if S is specified, the I/O area must be at least 120 bytes.
SYNC	yes	yes	R	Synchronization.
XRST	yes	yes	R	Restart.
Notes: R = required; O = optional; N = none The data statement is required on the AIB interface. Valid only on the AIB interface. SNAP is a Product-sensitive Programming Interface. STAT is a Product-sensitive Programming Interface.