As I could not find the answer anywhere else:
What is SGBD? Is it "Système de Gestion de Bases de Données" (Database management system)?
E.g. it is used in responses to these two Stack Overflow questions:
Yes you're right, I confirm that in French we use the abbreviation SGBD for 'Système Gestion de Base de Données' (DataBase Management System / DBMS) to which we can sometimes add R (SGBDR) 'Système Gestion de Base de Données Relationnelle' (RDBMS).