In the late 80’s and early 90’s of the last century, the first object DBMS systems began to appear, and in the late 90’s the first object-relational DBMS systems.
ABSTRACT
Today, almost all RDBMS products have the prefix “O”, ie they are presented as ORDBMS (object-relational DBMS), supporting (at least some) object-relational capabilities defined in the SQL: 1999 and SQL: 2003 standard.
But the well-known scientist in the field of relational models and relational systems, C. J. Date, wrote in his book “Database in Depth” (2005, p. 32): “After all, the whole point of an “object/relational” system is precisely that we can have attribute values in relations that are of arbitrary complexity. Perhaps a better way to say it is this: a proper object/relational system is just a relational system with proper type support – which just means it’s a proper relational system, no more and no less.”.
The paper presents the object-relational capabilities of Oracle 11g (and 10g) DBMS and gives recommendations on how these capabilities should be used (also, how they should not be used!), in accordance with Date’s work.