| Section 4.17.2 |
| A unique constraint is satisfied if and only if no two rows in a table have the same non-null values in the unique columns. |
| |
| Section 11.7 |
| 3) If <unique column list> UCL is specified, then |
| a) Each <column name> in the <unique column list> shall identify a column of T, and the same column |
| shall not be identified more than once. |
| b) The set of columns in the <unique column list> shall be distinct from the unique columns of any other unique constraint descriptor that is included in the base table descriptor of T. |
