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The Clash of the (database) Cultures
Relational
Objectoriented
Two strategies in order to combine the „cultures“:
(1) Relational – object-oriented
Example: Fastobjects‘ ODBC interface
(2) Object – relational
Example: SQL 3 or SQL:2003
Object-relational databases
based on SQL-3 are Complex objects
partwise according to Objekt identity
the Manifesto:
Encapsulation
P
P
No
Types (and Classes)
P
Class or Type Hierarchies
P
Overriding, overloading and late binding
No
Computational completeness
P
Extensibility
P
Persistence
P
Secondary storage management
P
Concurrency
P
Recovery
P
Ad Hoc Query Facility
P
Examples
Structures
table type
CREATE TYPE PersonType AS
(Name VARCHAR (30),
Address VARCHAR (50))
NOT FINAL;
CREATE TYPE StaffMemberType UNDER PersonType AS
(Salary DECIMAL (6))
NOT FINAL;
Inherited
type
CREATE TABLE StaffMember OF StaffMemberType
(REF IS oid SYSTEM GENERATED);
For more details see:
http://www.objs.com/x3h7/sql3.htm
Table definition
based on a type;
insertion of an OID
(2) Object-oriented database systems offer relational interfaces
Example: Fastobjects‘ ODBC interface
Architecture of FastObjects ODBC
FastObjects
database
Object-oriented
Relational
FastObjects
Engine
FastObjects
ODBC driver
C++ Application
(native API)
Access
database
Access Client
C++ Application
(ODBC API)
Access
database
Access
Engine
Access
ODBC driver