DBCC TRACEON - Enable trace flags.
DBCC TRACEOFF - Disable trace flags.
DBCC TRACESTATUS - Display the status of trace flags.

Syntax
DBCC TRACEON ( trace# [ ,...n ][ , -1 ] ) [WITH NO_INFOMSGS]

DBCC TRACEOFF ( trace# [ ,...n ] [ , -1 ] ) [WITH NO_INFOMSGS]

DBCC TRACESTATUS ( [ [trace# [,...n ] ] [,] [-1] ] ) [WITH NO_INFOMSGS]

Key:

trace# - Number of the trace flag(s)
-1 - Display the status of trace flags that are enabled globally.
NO_INFOMSGS - Suppress all information messages.

By default all trace flags that are enabled for the session are displayed.

Examples

-- Turn flag on
DBCC TRACEON (3205)
GO
-- Turn flag on globally
DBCC TRACEON (2528, -1)
GO
-- Turn flag off
DBCC TRACEOFF (3205);
GO
-- Show flag status
DBCC TRACESTATUS (2528, 3205)
GO

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