Using Trace Flags

DBCC Trace Flags

Although mostly undocumented, SQL Server provides a number of trace flags that can be used to further diagnose issues.  Trace flags are used to customize certain characteristics controlling how Microsoft® SQL Server™ operates.  Trace flags are turned on by executing a DBCC TRACEON statement and remain enabled in the server until disabled by executing a DBCC TRACEOFF statement or the SQL Server is restarted.  New connections into the server do not see any trace flags until a DBCC TRACEON statement is issued. Then, the connection will see all trace flags currently enabled in the server, even those enabled by another connection.  Executing DBCC TRACESTATUS will display those flags that are currently enabled.

For more information about trace flags, see your SQL Server Books Online.