| TABLE | data    |
| id    | INTEGER | PK |           | a comment        |
| name  | TEXT    |    | 'default' | another comment  |
| value | INTEGER |    | 1         | associated value |
| amount| MONEY   |    | -11.11    |                  |

| TABLE | pairs       |
| id    | INTEGER     | PK |         |                  |
| end1  | FK data(id) |    |         |                  |
| end2  | FK data(id) |    |         |                  |
| value | TEXT        |    |         |                  |

