Object Relational and Extended Relational Database Systems Chapter 13 Object Relational and Extended Relational Database Systems
Evolution RDBMS: relational data model ODBMS: object data model legacy DBMSs: hierarchical and network models ORDBMS enhance the capabilities of RDBMSs with some features in ODBMSs
classification of DBMS applications simple data, simple querying simple data, complex querying traditional RDBMSs complex data, simple querying ODBMSs complex data, complex querying ORDBMSs
Informix Universal Server: an ORDBMS how Informix Universal Server extends the relational data model support for additional or extensible data types support for user-defined routines (procedures or functions) implicit notion of inheritance support for indexing extensions data blades application programming interface (API)
extensible data type Data Blade modules (built-in types) 2-D geometric objects (points, lines, circles, ellipses) images time series text web pages constructs for additional types Opaque type Distinct type Row type Collection type
Opaque type User has to provide casting functions to convert an opaque object between its hidden representation in the server (database) and its visible representation as seen by client (calling program) send/receive converts to/from the server internal representation from/to the client representation import/export converts to/from an external representation for bulk copy from/to the internal representation
An example CREATE