Oracle Function-based Index
| CREATE INDEX | Required keywords. |
| index_name | Unique name for the index. |
| ON | Required keyword. |
| table_name | Unique table name. |
| function_expression | The expression of the function on which the index is based. |
| CREATE INDEX | Required keywords. |
| index_name | Unique name for the index. |
| ON | Required keyword. |
| table_name | Unique table name. |
| function_expression | The expression of the function on which the index is based. |
