TIMED_STATISTICS

Parameter type	Boolean
Default value	If STATISTICS_LEVEL is set to TYPICAL or ALL, then true If STATISTICS_LEVEL is set to BASIC, then false
Parameter class	Dynamic: ALTER SESSION, ALTER SYSTEM
Range of values	true | false

TIMED_STATISTICS specifies whether or not statistics related to time are collected.

Values:

• true

  The statistics are collected and stored in trace files or displayed in the V$SESSTATS and V$SYSSTATS dynamic performance views.

• false

  The value of all time-related statistics is set to zero. This setting lets Oracle avoid the overhead of requesting the time from the operating system. Normally, TIMED_STATISTICS should be false.

On some systems with very fast timer access, Oracle might enable timing even if this parameter is set to false. On these systems, setting the parameter to true can sometimes produce more accurate statistics for long-running operations.

See Also: Oracle9i Database Performance Tuning Guide and Reference for more information on setting this parameter and on performance diagnostic tools in general Appendix C, "Statistics Descriptions" indicates which statistics depend on the setting of this parameter.