This statement specifies the number of tasks for service requests.
Definition
A lower-level option of CPU-RESOURCES
Function
CPU-intensive activities, such as the sorting of intermediate results and some utility functions, can last a very long time. To avoid being blocked during this time, the SESAM/SQL DBH can relocate these CPU-intensive activities as separate tasks, which are then available for service requests.
At the end of the session, the DBH terminates all service tasks. Service requests that are still open or running are aborted.
You use the DBH option SERVICE-TASKS to specify how many service tasks are to be available at the beginning of the DBH session and the maximum number of service tasks that can be started in the course of the session.
You can also specify whether the DBH is to use the multitask sorting facility of the software product SORT.
You can also enter specifications for transferring information by email.
There must be no read password to the module library from which SESAM/SQL is started.
When SESAM/SQL is started, no temporary file must be used as a module library.
The module library must be available for the entire duration of the DBH session.
All files assigned with the link name BLSLIBnn, where nn = 00 to 99, when SESAM/SQL is started must be accessible for the entire duration of the DBH session.
You can adjust the values of the option during the DBH session by means of the MODIFY-SERVICE-TASKS administration statement (see "MODIFY-SERVICE-TASKS").
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Operands
SERVICE-TASKS = *STD
The number of service tasks is determined by default values; these are described under *PARAMETERS.
SERVICE-TASKS = *PARAMETERS(...)
INITIAL = 1 / <integer 0..32>
Number of service tasks started at the beginning of the DBH session.
The default value for INITIAL is 1, which means that when the DBH is loaded, at least one service task is started and immediately available for service requests. When using the linked-in DBH, no more than one service task can be started.
MAXIMUM = *STD / <integer 0..64>
Maximum number up to which further service tasks may be started during the DBH session.
The default value for MAXIMUM is the greater of the following two values (with a maximum of 64):
the maximum number of concurrent active threads, specified by means of the DBH option THREADS (see "THREADS")
the value assigned to the INITIAL operand
In the case of the independent DBH, note the following:
if you enter 0 for MAXIMUM, this value is automatically set to 1. If you specify a value for MAXIMUM that is greater than 0 but less than that for INITIAL, you receive an error message.In the case of a linked-in DBH, note the following:
no more than one service task is started, even if you specify a value greater than 1 for MAXIMUM. If you specify MAXIMUM = 0, no service task is started. In this case, the DBH can carry out the sorting of intermediate result sets as a subroutine in its own task. Other service requests, such as the utility statements COPY, LOAD and RECOVER, are rejected.
JOBCLASS = *STD / <name 1..8>
Name of the BS2000 job class.
The batch job is to run in the default job class or in a job class that you specify after making your selection.
The standard job class is the default job class for batch jobs of the DBH identifier. It is taken from the JOIN entry of the user ID.
JOBCLASS = *DBH-JOBCLASS
The name of the BS2000 job class is the job class of the DBH when the service task is started as long as the DBH is started as a batch job. In interactive mode the specification of *DBH-JOBCLASS is ignored and the procedure is the same as for JOBCLASS=*STD.
WORK-FILES =
Temporary SORT work files which are generated within a service task are created before each sort run and deleted after it.
WORK-FILES = *PUBLIC-DISK(...)
Temporary SORT work files are stored on a public disk.
CAT-ID = *STD / <cat-id>
Catalog ID of the pubset on which the temporary SORT work files are to be stored. The default is the DBH catalog ID.
PRIMARY-ALLOCATION = *STD / <integer 1..16777215>
Number of PAM pages for the initial allocation of memory space. The default value is 120.
SECONDARY-ALLOCATION = *STD / <integer 1..32767>
Number of PAM pages for subsequent extensions to files. The default value is 120.
WORK-FILES = *PRIVATE-DISK(...)
Temporary SORT work files are stored on a private disk.
CAT-ID = *STD / <cat-id>
Catalog ID of the pubset on which the temporary SORT work files are to be stored. The default is the DBH catalog ID.
PRIMARY-ALLOCATION = *STD / <integer 1..16777215>
Number of PAM pages for the initial allocation of memory space. The default value is 120.
SECONDARY-ALLOCATION = *STD / <integer 1..32767>
Number of PAM pages for subsequent extensions to files. The default value is 120.
DEVICE-TYPE = <structured-name 1..8>
BS2000 device type to which the required disks are assigned.
If you make an incorrect entry, the system prompts you in interactive mode to make the entry again (see the device type table in the BS2000 manual “ Commands”).
VOLUME = list-poss(6): <alphanum-name 1..6>
VSNs of the disks on which the file is to be created. Up to 6 VSNs are permitted, each of which can be specified only once. VOLUME is not evaluated unless the DEVICE-TYPE operand is specified.
RECORDS-PER-CYCLE = *STD / <integer 1..2147483647>
Number of records to be sorted per cycle by a sort subtask during multitask sorting. SESAM/SQL passes this value to the BS2000 utility SORT in the CYCLE parameter (see also the SORT manual “ SDF Format”). The “ Performance” manual describes the criteria on the basis of which the RECORDS-PER-CYCLE value should be assigned. The total number of records to be sorted divided by CYCLE is the optimal number of work files to be created. However, no more than 9 temporary work files can be created. The number of work files determines the number of sort subtasks started by the SORT utility (number of sort subtasks = number of work files minus 1). In single-task sorting, work files are not created unless one of the following operands is specified: CAT-ID, PRIMARY-ALLOCATION or DEVICE-TYPE.
*STD means that the DBH does not use the multitask sorting facility.
MAIL =
Controls the output of information by email.
MAIL = *NONE
The information is not sent by email.
MAIL = *PARAMETERS(...)
Controls the volume of information which is sent by email.
OUTPUT = *ALL
When the service task terminates its SYSLST file is sent by email to the address which is entered in the MAIL parameter file (see "Sending important information of the DBH session by email"). The MAIL parameter file must have been assigned with the link name SESMAIL when the DBH started.
“SYSLST (SVT, TSN=<tsn of the service task>” is entered under “Subject:”. The sender is the sender address entered in the MAIL parameter file under “SENDER=”. The SYSLST file is attached to the email.
OUTPUT = *ERROR
Only if the server task terminates with an error its SYSLST file is sent by email to the address which is entered in the MAIL parameter file (see "Sending important information of the DBH session by email"). The MAIL parameter file must have been assigned with the link name SESMAIL when the DBH started.
“SYSLST (SVT, TSN=<tsn of the service task>” is entered under “Subject:”. The sender is the sender address entered in the MAIL parameter file under “SENDER=”. The SYSLST file is attached to the email.
Information on service tasks
Information about the utilization of the service tasks in the current session is provided by the SESAM/SQL utility routine SESMON in the SERVICE TASKS form (see "DBH form SERVICE TASKS").