| Match tiles to sectors, and vice versa. |
| This table is designed to be queried in either direction - one can get all the tiles associated with a sector, or one can find all the sectors to which a tile belongs. |
| Index Type | Key or Field List |
| primary key | regionId, tile |
| foreign key | Sector(regionID) |
| foreign key | TileAll(tile) |
| covering unique index | tile, regionID |