TeraTeam UK Teradata DBA Definition
DBQL: Database Query Log
DBQL - Database Query Log
Database Query Log is an extremely useful tool to the Teradata DBA in terms of analysing resource usage as well as for security purposes.
Basically it is a log of queries submitted by users of the Teradata Database. It can record varying levels of detail but includes CPU usage, I/O and elapsed time and details of the objects accessed.
DBQL must be turned on for all users for whom query logging is required (Terateam Uk suggest all users).
Because it generates large volumes of data, a good housekeeping process is required to avoid excessive data build up.
Logging Options include:
With All - Includes all other options, uses a great deal of space, to be used with caution and normally only for selected users.
With Explain - keeps a log of the explain output
With Objects - Generates a lot of data but very useful for analysis of joins and indexes.
With SQL - records the entire SQL statement, needed in most enviornments
With StepInfo - generates a lot of data, useful in analysing query performance where performance is an issue. Normally recommended only for specific users for specific time periods to analyse issues.
DBQL is a massively important resource for the DBA and Terateam UK would recommend it's implementation, in an appropriate form for almost all Teradata implementations. Terateam UK have a great deal of experience in implementing and optimising DBQL.
