16.20 - Advantages of Manually Flushing Query Logs - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Data Definition Language Detailed Topics

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Release Date
March 2019
Content Type
Programming Reference
Publication ID
B035-1184-162K
Language
English (United States)

Using FLUSH QUERY LOGGING requests synchronously flushes all DBQL and TDWM caches across the whole system. All the PEs flush respective caches at the same time. When a FLUSH QUERY LOGGING request returns a success response to the client, the cache contents are written to their respective tables.

Note that submitting FLUSH QUERY LOGGING requests too frequently has the same negative performance impact as setting the DBS Control DBQL flag too low.

FLUSH QUERY LOGGING enables all the DBQL and TDWM caches to be flushed synchronously and does not return control to the client until all the caches have been flushed into the appropriate tables.