These columns represent information about the VH (Very Hot) cache, which holds the hottest permanent table cylinders.
Tables that are assigned a temperature of very hot are kept in the FSG cache as long as they:
- Stay very hot.
- Fit into the memory assigned. If the tables cannot fit, the FSG cache considers a sorted list of the hottest segments and assigns them to the very hot cache in temperature sorted order. The temperature of the segment is hot enough to qualify.
The temperature takes into account both physical and logical disk accesses and cache hits (such as, physical and logical I/Os).
| Column Name | Mode | Description | Data Type |
|---|---|---|---|
| VHLogicalDBRead | count | Number of logical reads from VH cache. This field is populated by the FSG subsystem. | FLOAT |
| VHLogicalDBReadKB | count | Volume of logical reads in KB from VH cache. This field is populated by the FSG system. | FLOAT |
| VHPhysicalDBRead | count | Number of very hot reads that were handled by physical disk I/O due to a VH cache miss (that is, data not found in the VH cache). This field is populated by the FSG system. | FLOAT |
| VHPhysicalDBReadKB | count | Volume of very hot reads in KB that were handled by physical disk I/O due to a VH cache miss. This field is populated by the FSG system. | FLOAT |