Design Relational Database - Use hierarchical datamodels or avoid them?

Question

I\'m designing a Database and I have some doubts on using Hierarchical datamodels in relational databases.

If I want to deal with categories, subcategories and paren

Answer 1

What do you mean by "hierarchical data model"? If you just mean modelling a hierarchy in a relational or SQL database then that's a perfectly common and reasonable thing to do. There is a significant quantity of database literature on the subject of how to model hierarchies relationally. There is nothing "non relational" about doing that.

However, the term Hierarchical Data Model more usually refers to a type of DBMS (not an RDBMS or SQL DBMS). Hierarchical / Network / Graph DBMSs operate on different principles to RDBMSs - they use navigational or pointer-based models rather than the relational model. The relational / SQL model has largely (but not entirely) superseded that type of DBMS. Unless you happen to be using a hierarchical type of DBMS then you don't need to worry about it.