When I create a new table in a in-Db workflow, I want to specify some contraints, especially the Primary Key/Foreign Key
For PK/FK, the UX could be either the selection of some fields of the flow or a free field (to let the user choose a constant).
From wikipedia :
In the relational model of databases, a primary key is a specific choice of a minimal set of attributes (columns) that uniquely specify a tuple (row) in a relation (table).[a] Informally, a primary key is "which attributes identify a record", and in simple cases are simply a single attribute: a unique id.
So, basically, PK/FK helps in two ways :
1/ Check for duplicate, check if the value inserted is legit
2/ Improve query plan, especially for join