Alsaleem B5 – Object oriented databases

Object oriented databases are also known as Object Database Management Systems (ODBMS). Object databases store objects rather than data such as integers, strings or real numbers. Objects consist of Attributes or Methods.

Attributes are data which defines the characteristics of an object. This data may be as simple as integers, strings, and real numbers or it may be a reference to a more complex object. However, Methods are the behavior of an object and are what was formally called procedures or functions.

Therefore, it can be stated that object oriented databases contain both executable code and data. There are other characteristics of objects such as whether methods or data can be accessed from outside the object.

One other term used is Classes. Classes are used in object oriented programming to define the data and methods the object will contain. The class is like a template to the object. The class does not contain data or methods within itself but defines the data and methods that are contained in the object. Classes are used to represent a certain thing within the object. Classes may be used in object databases to recreate parts of the object that may not actually be stored in the database. Methods may not be stored in the database and may be recreated by using a class.

Object databases should be used when there is complex data or complex data relationships. This includes a many to many object relationships. Object databases should not be used when data is simple and relationships are simple.

Object oriented databases work well with:

• CAS Applications (CASE-computer aided software engineering, CAD-computer aided design, CAM-computer aided manufacture)
• Multimedia Applications
• Object projects that change over time.
• Trading and Commencing

Object oriented Database Advantages over RDL

• Objects don't require assembly and disassembly saving coding time and execution time to assemble or disassemble objects.
• Reduced paging
• Easier navigation
• Better concurrency control - A hierarchy of objects may be locked.
• Data model is based on the real world.
• Works well for distributed architectures.
• Less code required when applications are object oriented.

Object oriented Database Disadvantages compared to RDL

• Lower efficiency when data is simple and relationships are simple.
• Relational tables are simpler.
• Late binding may slow access speed.
• More user tools exist for RDL.
• Standards for RDL are more stable.
• Support for RDBMS is more certain and change is less likely to be required.

Sources:

http://searchoracle.techtarget.com/definition/object-oriented-database-management-system

http://www.comptechdoc.org/independent/database/basicdb/dataobject.html

Responding to peers

Egla Qori – Your explanation for the SQL language was very clear and helpful. The operations are mostly very common, I am not very sure but I believe I have used a SQL language for a previous class therefore I agree how important it is learning SQL to enable a user to interpret data.

Ronald Herazo -  You did a great job explaining what a relational database is and introducing the background knowledge needed to understand it helped a lot. My only point that I wish you explained better was the comparison at the end, I believe if you stated some examples it would have been clearer and more interesting.

Prahlad – I enjoyed your blog about databases. Introducing the concept then giving examples, furthermore introducing where and how it is used in firms and hot people work with databases really gives the reader a great idea. Very clear post, great examples and very straight forward.