Adding a Column to a Table

Maintaining Tables with Related Constraints › Impact of Changing Structure Definitions on Constraints › Adding a Column to a Table

Adding a Column to a Table

If you add a column to a table that has constraints defined, the constraints become invalid. This applies only if the column is not in a Unique or Foreign Key (see Adding a Column to a Key).

Type of Constraint	Effect on Constraint
Check and Foreign	Constraints become invalid because offsets stored in the object change. The constraints are rebound by SQL the next time the table is accessed.
Unique	Constraints become invalid because the length of the table and offsets change. The constraints are rebound by SQL the next time the table is accessed. The referencing constraints also become invalid and are rebound by SQL the next time the table is accessed.

Type of
Constraint

Effect on Constraint

Check and
Foreign

Constraints become invalid because offsets stored in the object change. The constraints are rebound by SQL the next time the table is accessed.

Unique

Constraints become invalid because the length of the table and offsets change. The constraints are rebound by SQL the next time the table is accessed.

The referencing constraints also become invalid and are rebound by SQL the next time the table is accessed.