SYSTEM Statement Parameters

SYSTEM statement parameters determine the behavior of the DC/UCF runtime system for the following:
idms19
SYSTEM statement parameters determine the behavior of the DC/UCF runtime system for the following:
  • Abend handling and timed functions
  • Backup and recovery
  • The operating environment
  • Print control
  • Program management
  • Record locking
  • Resource management
  • Run-unit management
  • Storage management
  • Storage protection
  • System monitoring
  • Task management
Function of SYSTEM Statement Parameters
The following table briefly describes the function of each SYSTEM statement parameter:
Parameters
Descriptions
Abend Handling and Time Parameters
Activate mechanisms to detect and process abending programs and tasks
ABEND STORAGE
Allocates storage for abend processing from a storage stack overflow in a task control element
CHKUSER TASKS
Allocates check-user subtasks to detect abnormally terminated external request units
DEADLOCK DETECTION INTERVAL
Specifies the frequency with which the system checks for deadlocks
DYNAMIC EXPANSION
Specifies whether the storage pool should be dynamically expanded if remaining free space is insufficient for a storage request.
EXTERNAL WAIT
Specifies the amount of time the system waits for an external request unit to issue a database request
INACTIVE INTERVAL
Specifies the amount of time the system permits a task to wait for a resource
INTERNAL WAIT
Specifies the amount of time the system permits an external request unit to wait for a resource
QUIESCE WAIT
Specifies the amount of time the system permits a task to wait for a quiesce operation to terminate before abnormally terminating the task
RECOVERY WAIT
Specifies the amount of time the system permits a task to wait for a resource to be recovered by a failed data sharing group member before abnormally terminating the task
RESOURCE TIMEOUT
Specifies the amount of time the system permits a terminal or external request unit to be inactive and identifies the program that the system invokes to handle resources that are associated with a terminal or external request unit that remains inactive beyond the specified time limit
RUNAWAY INTERVAL
Specifies the amount of time the system permits a task to execute without returning control to the system
SNAP SYSTEM
Specifies whether to write a system snap dump to the DC/UCF log.
SNAP SYSTEM PHOTO
Specifies whether to write a system photo snap to the DC/UCF log.
SNAP TASK
Specifies whether to write a task snap dump to the DC/UCF log.
SNAP TASK TRACE
Specifies whether to write task traces to the DC/UCF log.
SNAP TASK PHOTO
Specifies whether to write a task photo snap to the DC/UCF log.
TICKER INTERVAL
Specifies the frequency with which the system checks for time-related events (such as runaway tasks)
Backup and Recovery Parameters
Control journaling options
JOURNAL/NOJOURNAL RETRIEVAL
Specifies whether the system writes BGIN and ENDJ checkpoints to the journal file for transactions that perform no updates
JOURNAL FRAGMENT INTERVAL
Specifies the number of journal blocks to be written to the journal file before the system writes a dummy segment record to the journal file
JOURNAL TRANSACTION LEVEL
Directs the system to defer journal I/O based on the number of active transactions running in the system
QUEUE JOURNAL
Specifies whether the system writes after images of queue records to the journal file
Operating Environment Parameters
Identify the environment in which the system executes
CVNUMBER
Identifies the system to the CA IDMS SVC (z/OS, z/VSE systems only)
DESCRIPTION CODES
Specifies operator-message description codes (z/OS systems only)
EVAL
Controls date processing
EVAL BASE YEAR
Specifies the base year to be used by EVAL when doing built-in functions DATEDIFF and DATEOFF
EVAL CENTURY VALIDATION
Indicates whether century values are to be validated by EVAL when processing built-in functions that accept four-digit years, such as GOODDATEX
EVAL HIGH CENTURY
Specifies the highest century value that EVAL is to consider valid when processing built-in functions that accept four-digit years, such as GOODDATEX
EVAL LOW CENTURY
Specifies the lowest century value that EVAL is to consider valid when processing built-in functions that accept four-digit years, such as GOODDATEX
GENERATION IDENTIFICATION
Provides an identifier for the system options table
MESSAGE RETENTION
Specifies the time period that system retains messages that are generated by the SEND command
MULTIPLE SIGNONS
Specifies whether the same user-ID can be signed on to multiple interactive terminals simultaneously.
OPERATING SYSTEM
Identifies the host operating system
PAGE RELEASE
Invokes virtual storage operating system services to free real page frames (z/VSE systems only)
ROUTE CODES
Specifies operator-message routing codes (z/OS systems only)
SVC
Identifies the CA IDMS SVC used for communication between the system and programs executing outside the system region/partition (z/OS and z/VSE systems only)
SYSCTL
Defines the system control file that is used by programs executing outside the system region/partition
SYSTEM ID
Specifies the node name of the system
Print Control Parameters
Control printing options
OVERRIDING REPORT LINE LENGTH
Specifies the line length to be used for all reports that are generated within a DC/UCF system
PRINT KEY
Identifies the default control key that is used to print the contents of a terminal screen
PRINTER CHECKPOINT
Specifies the frequency with which the system writes checkpoints for each report as it is printed
PRINTER CONTROL
Specifies the printer form feed options
Program Management Parameters
Control program loading and execution
LOADLIST
Identifies the default load list that is used by the system
MULTIPLE ENCLAVE
Specify enclave sharing for the system
NEW COPY
Determines how the system handles attempts to load deleted programs
PROGRAM POOL
Specifies the size of the standard program pool for programs that use 24-bit addressing
REENTRANT POOL
Specifies the size of the program pool for reentrant programs that use 24-bit addressing
UNDEFINED PROGRAM COUNT
Enables automatic definition of programs at runtime
XA PROGRAM POOL
Specifies the size of the standard program pool for programs that use 31-bit addressing
XA REENTRANT POOL
Specifies the size of the program pool for reentrant programs that use 31-bit addressing
Database Locking Parameters
Allocate initial lock storage and determine when locks are maintained
RETRIEVAL LOCK/NOLOCK
Specifies whether the system maintains locks for records in areas that are accessed in shared retrieval usage mode
SYSLOCKS
Specifies an estimate for the maximum number of locks that are held concurrently within the system
UPDATE LOCK/NOLOCK
Specifies whether the system maintains locks for records in areas being accessed in protected update usage mode
Resource Management Parameters
Control the allocation of system resources
AREA ACQUISITION THRESHOLD
Specifies whether the system accumulates area locks when attempting to ready multiple database areas for a single database transaction
DPE COUNT
Specifies the number of elements available to prevent tasks from deadlocking when acquiring resources
ECB LIST
Specifies the size of the event control block list that is used to synchronize events between the DC/UCF system and the host operating system
CALL/DBIO/LOCK/STORAGE LIMIT
Establishes limits for resources that are used by individual tasks
LIMITS FOR ONLINE
Specifies whether the system enforces limits on task resource usage
QUEUE RETENTION
Specifies the time period that the system retains queues that are created dynamically
RCE COUNT
Specifies the number of resource control elements available to all tasks
REPORT RETENTION
Specifies the amount of time the system retains reports in the queue area
RLE COUNT
Specifies the number of resource link elements available to all tasks
SQL ROW LIMIT
Specifies the maximum number of rows that can be read or updated by a single SQL statement. Includes rows that are processed internally, for example, by a sort or an aggregate function, not only the number of rows updated or returned to the user. The calls to a table procedure or procedure are also counted toward the limit. SQL ROW LIMIT can be used to limit database I/O activity.
System Run Unit Management Parameters
Control the execution of run units that access the database and data dictionary
MAXIMUM ERUS
Specifies the maximum number of external request units the system can service concurrently
RUNUNITS FOR LOADER/
MSGDICT/QUEUE/
SECURITY/SIGNON/SYSTEM/DEST
Predefines system run units
Storage Management Parameters
Control the allocation of system storage
CUSHION
Specifies the amount of storage in the primary storage pool the system reserves for use by tasks that are already executing
CWA SIZE
Specifies the size of the common work area available to all tasks
ERUS FETCH PROTECT
Indicates whether the system allocates External Run Unit Storage (ERE/ESE) in a storage sub-pool that is or is not fetch protected.
RELOCATABLE THRESHOLD
Specifies the point at which the system writes relocatable storage to the scratch area
SCRATCH IN STORAGE
Enables storage allocation from the operating system for scratch processing and optionally its dynamic extension.
STORAGE POOL
Specifies the size of the primary storage pool
XA STORAGE POOL
Specifies the size of the 31-bit storage pool
Storage Protection Parameters
Control the use of storage protection
PROTECT/NOPROTECT
Enables programs to use storage protection
STORAGE KEY
Identifies the alternate storage protect key
System Monitoring Parameters
Provide a record of system status and activity
ABRU SNAP/NOSNAP
Specifies whether the system writes snap dumps to the system log for abended external request units
DEBUG MESSAGE BUFFERS
Specifies the number of buffers that are used by the CA IDMS online debugger
DUMP/NODUMP
Determines the conditions under which the system writes a memory dump
LOG
Specifies the file assignment for the DC/UCF system log
STATISTICS
Determines the types of statistics that are collected and the frequency with which statistics are written to the system log
SYSTRACE
Enables the system trace facility
USERTRACE
Enables the user trace facility
Task Management Parameters
Control the execution of tasks
MAXIMUM TASKS
Specifies the maximum number of online tasks the system can service concurrently
ON COMMIT
Specifies options that control commit behavior
ON ROLLBACK CONTINUE
Specifies options that control rollback behavior
STACKSIZE
Specifies the size of the storage stack in each task control element
TRANSACTION SHARING
Specifies the default transaction sharing option for all tasks within the syst
Overriding SYSTEM Statement Parameters
You can override certain SYSTEM statement parameters in one or more of the following ways:
The following table lists the SYSTEM statement parameters that can be overridden along with the applicable overrides.
Parameter
System Generation Override
Startup Override
Runtime Override
EVAL BASE YEAR
EVAL_BASE_YEAR=
EVAL CENTURY VALIDATION
EVAL_CENTURY_VALIDATION=
EVAL HIGH CENTURY
EVAL_HIGH_CENTURY=
EVAL LOW CENTURY
EVAL_LOW_CENTURY=
CUSHION
CUSH=
DCMT VARY STORAGE POOL 0 CUSHION
CVNUMBER
CVNUM=
DPE COUNT
DPECOUNT=
DEADLOCK DETECTION INTERVAL
DCMT VARY DEADLOCK
DUMP/NODUMP
DUMP/NODUMP
ECB LIST
ECBLIST=
EXTERNAL WAIT
TASK statement EXTERNAL WAIT
EXTWAIT=
DCMT VARY TASK EXTERNAL WAIT
DCMT VARY DYNAMIC TASK EXTERNAL WAIT
INACTIVE INTERVAL
TASK statement INACTIVE INTERVAL
INACTINT=
DCMT VARY TIME STALL
INTERNAL WAIT
INTWAIT=
JOURNAL/ NOJOURNAL RETRIEVAL
JOURRET/ NOJOURRET
JOURNAL FRAGMENT INTERVAL
DCMT VARY JOURNAL
JOURNAL TRANSACTION LEVEL
DCMT VARY JOURNAL
LIMIT FOR ONLINE
TASK statement LIMITs
DCMT VARY TASK LIMITs
LIMITS FOR ONLINE
DCMT VARY LIMITS
LOADLIST
DCUF SET LOADLIST
MAXIMUM ERUS
MAXERUS=
MAXIMUM TASKS
MAXTASK=
DCMT VARY ACTIVE TASK MAX TASK
MULTIPLE ENCLAVE
PROGRAM statement MULTIPLE ENCLAVE
DCMT VARY PROGRAM MULTIPLE ENCLAVE ON/OFF
DCMT VARY DYNAMIC PROGRAM MULTIPLE ENCLAVE ON/OFF
PRINT KEY
TASK statement PRINT KEY
PRINTER CHECKPOINT
LTERM statement PRINTER CHECKPOINT
PRINTER CONTROL
LTERM statement PRINTER CONTROL
PROGRAM POOL
PROGPOOL=
PROTECT/ NOPROTECT
PROTECT/ NOPROTECT
QUIESCE WAIT
TASK statement QUIESCE WAIT
DCMT VARY TASK QUIESCE WAIT
DCMT VARY DYNAMIC TASK QUIESCE WAIT
DCMT VARY TIME QUIESCE WAIT
RECOVERY WAIT
DCMT VARY TIME RECOVERY WAIT
RCE COUNT
RCECOUNT=
RESOURCE TIMEOUT INTERVAL
TASK statement RESOURCE TIMEOUT INTERVAL
RESOURCEINT=
DCMT VARY TIME RESOURCE INTERVAL
DCMT VARY TASK RESOURCE INTERVAL
RESOURCE TIMEOUT PROGRAM
TASK statement RESOURCE TIMEOUT PROGRAM
RESOURCEPGM=
/RESOURCEPGMV=
DCMT VARY TIME RESOURCE PROGRAM
DCMT VARY TASK RESOURCE PROGRAM
RLE COUNT
RLECOUNT=
RUNAWAY INTERVAL
RUNAWAY=
DCMT VARY TIME RUNAWAY
SQL ROW LIMIT
TASK statement SQL ROW LIMIT
DCMT VARY TASK SQL ROW LIMIT
STACKSIZE
STACKSIZ=
STATISTICS INTERVAL
DCMT VARY STATISTICS INTERVAL
STATISTICS TASK
TRANSACTION/NOTRANSACTION
DCMT VARY STATISTICS TRANSACTION
STORAGE POOL
STGPOOL
SYSLOCKS
SYSLOCKS=
SYSTRACE
SYSTRACE/ NOSYSTRACE/ SYSTRACENUM=
DCMT VARY SYSTRACE
TICKER INTERVAL
TICKINT=
DCMT VARY TIME TIMER
USERTRACE
USERTRACE/ NOUSERTRACE/ USERTRACESIZ=