SAP ABAP Data Element DB2BSTHITR (Buffer hit ratio)
Hierarchy
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SAP_BASIS (Software Component) SAP Basis Component
⤷
BC-DB-DB2 (Application Component) DB2 for z/OS
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STU2 (Package) CCMS for DB2 for OS/390
SAP_BASIS (Software Component) SAP Basis Component⤷
BC-DB-DB2 (Application Component) DB2 for z/OS⤷
STU2 (Package) CCMS for DB2 for OS/390
Basic Data
| Data Element | DB2BSTHITR |
| Short Description | Buffer hit ratio |
Data Type
| Category of Dictionary Type | Direct Type Entry | |
| Type of Object Referenced | No Information | |
| Domain / Name of Reference Type | ||
| Data Type | CHAR | Character String |
| Length | 7 | |
| Decimal Places | 0 | |
| Output Length | 7 | |
| 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 | Hit ratio |
| Long | 20 | Buffer hit ratio |
| Heading | 0 |
Documentation
Definition
The total number of GETPAGE operations minus the number of pages read from DASD (both synchronously and using prefetch), divided by the total number of GETPAGE operations, and multiplied by 100.
The highest possible hit ratio is 100%, that is, when every page requested is always in the buffer pool. If the requested page is not in the buffer pool, the hit ratio is 0% or less. If the hit ratio is negative, this means that prefetch brought pages into the buffer pool that are not subsequently referenced, either because the query stops before it reaches the end of the table space, or because the prefetched pages are stolen by DB2 for reuse before the query can access them.
History
| Last changed by/on | SAP | 20110908 |
| SAP Release Created in |
