default trace enabled Option
Use the default trace enabled option to enable or disable the default trace log files. The default trace functionality provides a rich, persistent log of activity and changes primarily related to the configuration options.
The default trace logs can be opened and examined by SQL Server Profiler or queried with Transact-SQL by using the fn_trace_gettable system function. SQL Server Profiler can open the default trace log files just as it does normal trace output files. The default trace log is stored by default in the \MSSQL\LOG directory using a rollover trace file. The base file name for the default trace log file is log.trc. In a typical installation of SQL Server, the default trace is enabled and thus becomes TraceID 1. If enabled after installation and after creating other traces, the TraceID can become a larger number.
For more information about using SQL Server Profiler to view this trace file, see How to: Open a Trace File (SQL Server Profiler)
The following statement opens the default trace log in the default location:
SELECT * FROM fn_trace_gettable ('C:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\LOG\log.trc', default) GO
When set to 1, the default trace enabled option enables Default Trace. The default setting for this option is 1 (ON). A value of 0 turns off the trace.
The default trace enabled option is an advanced option. If you are using the sp_configure system stored procedure to change the setting, you can change the default trace enabled option only when show advanced options is set to 1. The setting takes effect immediately without a server restart.