This statement sets the size of the work container.
Definition
A lower-level DBH option of STORAGE-SIZE
Function
The SESAM/SQL DBH checks that each statement is lexically, syntactically and semantically correct. Based on a correct statement or subarea of a statement, the DBH generates an optimized format known as the internal statement format.
Based on a CALL DML statement, the DBH generates the internal statement format directly. Based on an SQL statement, the DBH initially generates an SQL access plan, i.e. an evaluation rule for the SQL statement. An SQL access plan consists of at least one but usually several subareas known as SQL scans. The optimized format of a scan forms the internal statement format.
The internal statement formats are stored for further processing in the work container so that follow-up statements can refer back to them.
The DBH option WORK-CONTAINER allows you to adjust the size of the work container to the requirements of the application. The size of the work container is specified in units of 1 Kbyte.
You can adjust the values of the option during the DBH session by means of the MODIFY-STORAGE-SIZE administration statement (see "MODIFY-STORAGE-SIZE").
WORK-CONTAINER | ||||||||||||||||
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Operands
WORK-CONTAINER = *STD
The default value for the size of the work container is described under *PARAMETERS(...).
WORK-CONTAINER = *PARAMETERS(...)
Changes the size of the work container.
INITIAL = *STD / <integer 24..1000000>
Initial size of the work container in Kbytes. DBH carries out an internal comparison with the initial value of SUBORDERS when an initial value is specified:
Minimum value (or default value if no value was specified explicitly) for INITIAL for WORK-CONTAINER:
(Initial value of SUBORDERS + x) * 4 Kbyte
The additional amount x is calculated in the same manner as the additional amount for the initial value of TRANSFER-CONTAINER (see "TRANSFER-CONTAINER").
MAXIMUM = *STD / <integer 24..1000000>
Maximum size of the work container in Kbytes. DBH carries out an internal comparison with the maximum value of SUBORDERS when a maximum value is specified:
Minimum value (or default value if no value was specified explicitly) for MAXIMUM for WORK-CONTAINER:
(Maximum value of SUBORDERS+ x) * 4 Kbyte
The additional amount x is calculated in the same manner as the additional amount for the maximum value of TRANSFER-CONTAINER (see "TRANSFER-CONTAINER").
Space required to store the internal statement format in the WORK-CONTAINER
A resource bottleneck can be prevented for WORK-CONTAINER if its maximum size is the product of the maximum number of SUBORDERS and the space required to store an average internal statement format. The space required to store an average internal statement format can be derived from the following table. It depends on the DBH option COLUMNS (see "COLUMNS"f).
Average number of COLUMNS in the | Space required to store internal statement |
up to 1 | 12 |
up to 28 | 16 |
up to 63 | 20 |
up to 93 | 24 |
up to 122 | 28 |
up to 151 | 32 |
up to 210 | 40 |
up to 268 | 48 |
up to 327 | 56 |
up to 385 | 64 |
up to 438 | 72 |
up to 502 | 80 |
up to 561 | 88 |
up to 619 | 96 |
up to 736 | 112 |
up to 853 | 128 |
up to 970 | 144 |
up to 1024 | 152 |
Table 10: Space required to store internal statement formats
Information on the work container
You can obtain information on the work container and its extensions from the operational statistics of the SESAM/SQL monitor SESMON.
The “SYSTEM-INFORMATION” form indicates the size of the container, the percentage of its capacity being used, the number of area requests made, and the number of times the container has been accessed (see "DBH form SYSTEM INFORMATION").
The “ Performance” manual describes the cases in which it makes sense to modify the container size at the next DBH startup.