Vantage logs estimated and actual memory use for each request step in DBQLogTbl. Use TASM to identify requests that use large amounts of memory, then classify or throttle these requests appropriately. XML functions, some aggregations, hash joins, and queries that reference Native Object Store tables consume unusually high levels of memory.
Teradata recommends that you use Memory Usage primarily for throttles.
You can specify Memory Usage as a criterion for a throttle in the Throttles view, Classification tab, Query Characteristics classification criteria. The choices for Memory Usage are:
- Increased
- Large
- Very large
The range of memory associated with each category is defined in the default memory usage thresholds for your platform configuration. To see the defaults, look under System Settings in Viewpoint Workload Designer.
The request memory estimate represents peak use, typically by the largest step.