Disabling Constraints (version 6.5)

You can disable constraints by using:

• SET DISABLE_DEF_CNST_CHK option

  Disables deferred constraint checking for the session. Constraints that have been disabled by using the NOCHECK option or NOT FOR REPLICATION option are checked individually.

• NOCHECK option in ALTER TABLE statement

  Temporarily disables constraint checking for a foreign key or a check constraint. The constraint is disabled and can be re-enabled rather than re-created.

• NOT FOR REPLICATION in ALTER TABLE or CREATE TABLE statements

  Disables foreign key constraint checks on data inserted by distribution during replication.

Disabling constraints can improve performance and streamline replication processes. For example, when rebuilding or replicating databases at a remote site there is no need to repeat constraint checks because the integrity of the data was checked when it was entered into the original database.

For more information about disabling constraints, see SET Statement, ALTER TABLE Statement, and CREATE TABLE Statement.