Does the subTable hierarchy need to form a forest?


#1

The API documentation seems to imply (but without being explicit) that there is a tree structure to the data tables, starting from the root-level tables with each having a distinct set of subTables and sub-sub-Tables.

But the API endpoint to link parent and child table could conceivably be used to form more complicated dependency graphs. One could for example have the same subTable included in more than one root table, thereby reusing field definitions. OTOH, this adds complexity. Cycles should certainly be avoided (but may be hard to detect).


#2

Hi @thiloplanz,

Yes, practically the structure is more of a DAG (Directed Acyclic Graph) than a tree. Nevertheless, we assume JSON data structures to be the primary format of data structures coming in and out, which when serialised to a portable format only allow for forest-like structures.

Currently there is no explicit checking for cycles, but as you have observed allowing for very generic dependency graphs would mean a lot of added complexity and most likely should be avoided, at least until there is a clear need for them.

Best,
Aiste