@volpeon I recently-ish ran into a fun problem with one component of SAP while doing some database development. They were using SAP to push some data down into a certain table. We had a foreign key constraint set up to use this table - because, you know, relational database. But we had to delete it because apparently what SAP does is just drop and recreate the table with the data every 24 hours - which means the table can't update if there's a foreign key constraint that's using it.
So, no relationships in your relational database, because SAP says fuck you.