Property Description
Parameter type Boolean
Default value false
Range of values true | false

SQL_TRACE enables or disables the SQL trace facility. Setting this parameter to true provides information on tuning that you can use to improve performance. You can change the value using the DBMS_SYSTEM package.


Using this initialization parameter to enable the SQL trace facility for the entire instance can have a severe performance impact. Enable the facility for specific sessions using the ALTER SESSION statement. If you must enable the facility on an entire production environment, then you can minimize performance impact by:
  • Maintaining at least 25% idle CPU capacity

  • Maintaining adequate disk space for the USER_DUMP_DEST location

  • Striping disk space over sufficient disks

See Also:

Oracle Database Performance Tuning Guide for more information about performance diagnostic tools


The SQL_TRACE parameter is deprecated. Oracle recommends that you use the DBMS_MONITOR and DBMS_SESSION packages instead. SQL_TRACE is retained for backward compatibility only.