What is object oriented database?

An object-oriented database (OODB) is a database management system (DBMS) in which information is represented in the form of objects as used in object-oriented programming. Object databases are different from relational databases which are table-oriented. A third type, object–relational databases, is a hybrid of both approaches.

OODBs store data as objects, which are data structures that contain both data and methods. The data in an object is called its state, and the methods are called its behavior. Objects are related to each other through object-oriented relationships, such as aggregation, composition, and inheritance.

OODBs offer a number of advantages over relational databases, including:

• Increased data modeling flexibility: OODBs allow data to be modeled more closely to the way it is used in object-oriented programming languages. This can lead to more efficient and effective data access and manipulation.
• Improved performance: OODBs can often access data more efficiently than relational databases, because they do not need to translate object-oriented data into relational data.
• Reduced data redundancy: OODBs can reduce data redundancy by storing data only once, in the object itself. This can improve data integrity and performance.

However, OODBs also have some disadvantages, including:

• Higher cost: OODBs are typically more expensive than relational databases.
• Limited availability: There are fewer OODB vendors than relational database vendors.
• Lack of standards: There is no standard object-oriented data model, which can make it difficult to move data between different OODBs.

Overall, OODBs are a good choice for applications that require increased data modeling flexibility, improved performance, and reduced data redundancy. However, they may not be the best choice for all applications, due to their higher cost and limited availability.

Here are some examples of object-oriented databases:

• Objectivity/DB
• GemStone/S
• ObjectStore
• MongoDB
• Neo4j

These databases are all commercial products, but there are also a number of open source object-oriented databases available, such as:

• BerkeleyDB
• H2
• HSQLDB
• Apache Derby

These open source databases are a good option for developers on a budget.