Internal Architectures for Object-Relational DBMS Engines The design and implementation of SQL DBMS products is a subject covered in courses at many major universities. In this talk we will focus on the differences between the engineering found in products built with SQL-92 in mind and those research and commercial engines that support object-relational features: extensible typing, inheritance, polymorphism and so on. We will briefly introduce the relevant differences between the SQL-92 and Object-Relational data models and then explain how the communications, query processing, query execution and transactional storage modules of a SQL-92 RDBMS must be modified. We will touch on how the various commercial products have addressed these challenges.