17.05 - TIM Columns - Teradata Database

Teradata Vantageā„¢ - Resource Usage Macros and Tables

prodname
Advanced SQL Engine
Teradata Database
vrm_release
17.00
17.05
created_date
June 2020
category
Administration
User Guide
featnum
B035-1099-170K

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