Many paths to the same place
In other to build the index each table must map back to the primary table along exactly one path. Paths are defined by database relationships. Of course most databases do have cycles in their relationship graphs. To combat this issue you can resolve duplicates paths explicitly. When more than one path exists between a non-primary table and the primary table, the graph is in an invalid state. To resolve this issue the "Resolve Duplicate Paths" dialog presents you with all paths between these two tables. You may then choose which one to follow. Once a path is choose the invalid state of the dGraph is resolved. When building an index based on the data in the secondary table the data is linked to the primary table based on explicitly defined path.
In the above graphic, the state table has four different paths to the primary table. Before a dGraph can be built, we need to define the path to use because the state value may be different depending on which path is taken. When the above dGraph is built, the data for fields derived from the State table will join the USER_ACCOUNT table and then to the primary table LISTING.
