Specified interim deferred violation checking and was used for efficiency purposes in Microsoft® SQL Server™ version 6.x.
Important SET DISABLE_DEF_CNST_CHK is included for backward compatibility only. The functionality of this statement is now built into Microsoft SQL Server 2000. In a future version of SQL Server, SET DISABLE_DEF_CNST_CHK may not be supported.
If the compatibility level is set to 60 or 65, executing this statement does nothing. However, if the compatibility level is set to 70, executing this statement does nothing, and SQL Server returns a warning message. For more information about setting compatibility levels, see sp_dbcmptlevel