LONGQUERYTIMETHRESHOLD

This Essbase configuration setting enables capturing statistics on long-running grid and MDX queries. This setting lets you specify the lowest query-time length, in seconds, for which you want to capture statistical information.

When you enable this configuration, Essbase:

briefly summarizes query performance in the Oracle Diagnostic Log (ODL) for each query running longer than the specified time value
sets a threshold/filter on what is logged for query tracing (when the TRACE_REPORT setting is enabled)

Syntax

LONGQUERYTIMETHRESHOLD n

Where n is a number of seconds. If set to 0, then this setting is off (this is the default). If set to -1, this setting is always on.

Example

LONGQUERYTIMETHRESHOLD 60

Specifies statistics collection for queries running 60 seconds or longer.

Configuring Ongoing Query Tracing

Use the configuration settings TRACE_REPORT and LONGQUERYTIMETHRESHOLD together to manage the query tracing information that should be collected for the cube in the application’s Oracle Diagnostic Log (ODL), and/or printed to trace_report.log.

You can enable TRACE_REPORT for tracking general query performance, but Oracle recommends filtering out all but the longest running queries by also setting LONGQUERYTIMETHRESHOLD.

Ideally,

Configure Essbase to only log information for the top 5 percent of longest-running queries. If you don't know this value, 60 seconds may be a good place to start.
Regularly check that log files do not grow too large

Configuration Type	TRACE_REPORT value	LONGQUERYTIMETHRESHOLD value	Effect on Logs
ODL only, with threshold	Set to 0 (or not set at all)	Set to a value n (seconds) that is greater than 0	Performance metrics on all queries running longer than n seconds are printed to the application’s ODL log.
ODL and trace, with threshold	Set to -1	Set to a value n (seconds) that is greater than 0	Performance metrics on all queries running longer than n seconds are printed to the application ODL log. Information on queries running longer than n seconds is printed to `trace_report.log`.
Trace without threshold - not recommended!	Set to -1	Set to 0 (or not set at all)	Information on all queries, regardless of running time, is printed to `trace_report.log`. This configuration is not recommended, because `trace_report.log` can become too large if not filtered using a threshold, and query performance is affected if the threshold is too low.

The trace_report log is located in <Domain Home>/servers/<Essbase-Managed-Server-Name>/logs/essbase/essbase/app/<application-name>/<cube-name>/trace_report.log.

The application ODL log is located in <Domain Home>/servers/<Essbase-Managed-Server-Name>/logs/essbase/essbase/app/<application-name>/<application-name>_ODL.log.

See Environment Locations in the Essbase Platform.

When to Use Different Query Tracing Options

The QUERYTRACE configuration setting is designed for debugging a single query, in case any problems are observed. It prints the trace log to the cube directory as query_trace.txt, and the file is cleared by default before each query execution. QUERYTRACE should not be left enabled in the application configuration for long term use, as it may affect performance.

The TRACE_REPORT configuration setting provides fewer details than QUERYTRACE, but is able to trace multiple, concurrent queries. TRACE_REPORT is a good option for gathering information on many concurrent queries running over a period of time. For more details, see Configuring Ongoing Query Tracing.

Enabling query logging by setting the QUERYLOG parameter in dbname.cfg (in the cube directory) is designed for tracking user query patterns for a cube, in XML format.