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Object-Oriented DataBases - Coggle Diagram
Object-Oriented DataBases
Object-oriented software system
object
instance of object type
operation
set of actions on object
object type
concept about which data is stored
defined set of operations
method
way of performing operation
encapsulation
packaging of data structure, operations
inheritance
subclass inherit properties
polymorphism
different forms of object/operation
Motivation
storing large amounts of complex data
integrating complex data with simple data
Object-oriented methodologies
Multimedia systems
Geographic information systems
CAD systems
Document storage and retrieval systems
Advantages
complexity hiding
code reusability
polymorphism
encapsulation
Architectures for Object Database Management
Specialized Media Servers
Disadvantages
limited operations
sacrifice flexibility
limited transaction
no jointly optimizing retrieval
no indexing techniques
better performance
Object Database Middleware
location independence
transaction processing
slow because two-phase commit
slow because concurrency control
way to integrate complex data
relieves of knowing API
lack of integration with DBMS
Large Objects and External Software
storing complex data in column
as binary object
as text large object
Disadvantages
impossible optimization
additional disk accesses
order of large objects != order of other table data
simple approach
storing all complex data
Object Relational Database Management Systems for User-Defined Types
support user-defined types
video
image data
time series
spatial data
almost any kind of complex data
Disadvantages
implementation errors affect data integrity
user types -> viruses
compromised reability
Abilities
extend prebuilt types
create new user types
defined methods
collection of prebuilt user types
storage structures created
different customers' requirements
variety of approaches