17.10 - DBQL_AWTDPS_CacheMaximum - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - Database Utilities

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Configuration
Publication ID
B035-1102-171K
Language
English (United States)

Limits the size to which the per-AMP AWT DBQL Performance Stats (DPS) cache can grow. This cache holds DBQL request and step data for active requests.

Field Group

Performance

Valid Range

1024 to 16384 KB

1024 KB holds approximately 2,500 cache entries.

Default

8192 KB

Changes Take Effect

After the DBS Control Record has been written.

Usage Notes

  • When the cache has grown to the set maximum size, no further DBQL AMP data is cached, and the accuracy of query performance statistics can degrade.
  • If you reduce the size of the cache maximum to something below the current actual size of the cache, the current cache will neither shrink nor grow, but space in the current cache can be dynamically reused. The memory currently allocated to the cache is not released until the next database restart.
  • If you see a 9666 information event logged to /var/log/messages, you should increase the value of this field.
  • Teradata recommends you increase the value of this field in 4096 KB (4 MB) increments.

Related Information

For more information on… See…
BEGIN QUERY LOGGING, END QUERY LOGGING, and FLUSH QUERY LOGGING statements Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.
tracking processing behavior with the DBQL Teradata Vantage™ - Database Administration, B035-1093.