Hierarchy
SAP_BASIS (Software Component) SAP Basis Component⤷
BC-DB-DB2 (Application Component) DB2 for z/OS⤷
STU3 (Package) Development Class for Database Monitor
Basic Data
| Data Element | DB2VPSHORT |
| Short Description | Number of Virtual Pool Shortages |
Data Type
| Category of Dictionary Type | D | Domain |
| Type of Object Referenced | No Information | |
| Domain / Name of Reference Type | DB2DEC20V | |
| Data Type | DEC | Counter or amount field with comma and sign |
| Length | 20 | |
| Decimal Places | 0 | |
| Output Length | 27 | |
| Value Table |
Further Characteristics
| Search Help: Name | ||
| Search Help: Parameters | ||
| Parameter ID | ||
| Default Component name | ||
| Change document | ||
| No Input History | ||
| Basic direction is set to LTR | ||
| No BIDI Filtering |
Field Label
| Length | Field Label | |
| Short | 0 | |
| Medium | 15 | VP shortages |
| Long | 22 | Virtual pool shortages |
| Heading | 0 |
Documentation
Definition
The number of virtual pool shortages is defined as
QBSTXFL + QBSTXFV + QBSTWFD + QBSTWFF + QBSTJIS + QBSTPQF + QBSTPL1 + QBSTPL2
where
QBSTXFL:
Number of times that a usable buffer could not be located in the virtual buffer pool because the virtual buffer pool was full.
QBSTXFV:
Number of virtual buffer pool or hiperpool expansion failures caused by a shortage of virtual storage.
QBSTWFD:
Total number of work files (runs) that were rejected during all merge passes because of insufficient buffer resources.
This counter and QBSTWFF can be used to determine the average number of work files that cannot be honored at each merge pass because of insufficient buffer pool space.
QBSTWFF:
Number of times that the merge pass was not efficiently performed because of a shortage of buffer space.
This counter is incremented for each merge pass when the maximum number of work files allowed is less than the number of work files requested. The maximum number of work files allowed is computed as:
Buffers consumed = 2 * (Work files already allocated)
Buffers available = (sequential steal threshold * buffer pool size - buffers consumed)
Max work files allowed = buffers available /(2 * 8)
QBSTJIS:
Total number of requested prefetch I/O streams that were denied because of a storage shortage in the buffer pool.
For example, if 100 prefetch I/O streams are requested and only 80 are granted, then 20 is added to this counter.
QBSTPQF:
Total number of times during this statistics interval that DB2 could not allocate the requested number of buffer pages to allow a parallel group to run to the planned degree. This is caused by a storage shortage in the buffer pool.
QBSTPL1
Total number of occurrences when the prefetch quantity is reduced from normal to one-half of normal.
The normal size is dependent on the size of the buffer pool. This counter indicates when DB2 had to reduce sequential prefetch quantity to continue to execute concurrently with parallel query processing in the system.
QBSTPL2:
Total number of occurrences when the prefetch quantity is reduced from one-half to one-quarter of normal.
The normal size is dependent on the size of the buffer pool.
History
| Last changed by/on | SAP | 20110908 |
| SAP Release Created in | 700 |
