Sort sequence and constraints

 

Unique constraints are implemented with indexes. If the table on which a unique constraint is added is defined with a sort sequence, the index is created with the same sort sequence.

If defining a referential constraint, the sort sequence between the parent and dependent table must match.

The sort sequence used at the time a check constraint is defined is the same sort sequence the system uses to validate adherence to the constraint at the time of an INSERT or UPDATE.

 

Parent topic:

Sort sequences and normalization in SQL