The Object-Oriented Database System Manifesto by Engin Deveci

Three Points Characterize Lack of a common data model Lack of formal foundations Strong experimental activity

Must Satisfy Three Criteria Should be a DBMS Should be an object oriented system Should be consistent with object oriented languages

Main Features and Characteristics of OODBMS Mandatory Features Optional Features Open Features

Mandatory Features Features for general databases Features for object oriented databases

Features for General Databases Persistence Secondary storage management Concurrency Recovery Ad-Hoc query facility

Features for Object Oriented Databases Complex objects Object identity Encapsulation Types and classes Inheritance Overriding combined with late binding Extensibility Computational completeness

Thou shalt support complex objects Simple objects Integer, characters, byte string, boolean, float, vs. Complex objects Tuples, sets, bags, lists, arrays

Complex Objects Cont’d Thou shalt support complex objects Complex Objects Cont’d Object constructers must be orthogonal Appropriate operators must be provided

Thou shalt support object identity Object sharing Object updates

Thou shalt encapsulate thine objects Encapsulation Interface and implementation Modularity

Thou shalt support types and classes Supporting the notion of class Supporting the notion of type

Class or Type Hierarchies Thine classes or types shalt inherit from their ancestors Class or Type Hierarchies Substitution inheritance Inclusion inheritance Constraint inheritance Specialization inheritance

Thou shalt not bind prematurely Late Binding Overriding Overloading Late binding

Computational Completeness Thou shalt be computationally complete Computational Completeness SQL is not computationally complete Reasonable connection to existing programming languages

Thou shalt be extensible Extensibility System defined types User defined types No distinction in usage Distinction in low level support

Thou shalt remember thy data Persistence Data survival Should be orthogonal Should be implicit

Secondary Storage Management Thou shalt manage very large databases Secondary Storage Management Index management Data management Data clustering Data buffering Access path selection Query optimization

Thou shalt accept concurrent users Concurrency Same level of service Harmonious coexistence Atomicity of a sequence of operations Controlled sharing Serializability of operations

Thou shalt recover from hardware and software failures Recovery Back to coherant state of data Processor failures Disk failures

Thou shalt have a simple way of querying data Ad Hoc Query Facility Should be high level Should be efficient Should be application independent

No Consensus View definition and derived data Database administration utilities Integrity constraints Schema evolution facility

Optional Features Multiple inheritance Type checking and type inferencing Distribution Design transactions Versions

Open Features Programming paradigm Representation system Type system Uniformity

Conclusion Thou shalt question the golden rules Q&A