Which of the following correctly best describes an object-oriented database?
A.
When an application queries for data, it receives both the data and the procedure.
B.
It is structured similarly to a mesh network for redundancy and fast data retrieval.
C.
Subject must have knowledge of the well-defined access path in order to access data.
D.
The relationships between data entities provide the framework for organizing data.
Explanation:
A: In an object-oriented database, objects are instantiated when needed, and the data and procedure (called method) go with the object when it is requested. This differs from a
relational database, in which the application uses its own procedures to obtain and process data when retrieved from the database.
B is incorrect because a mesh network is a physical topology and has nothing to do with databases. A mesh topology is a network of interconnected routers and switches that
provides multiple paths to all the nodes on the network. In a full mesh topology, every node is directly connected to every other node, which provides a great degree of redundancy. In
a partial mesh topology, every node is not directly connected. The Internet is an example of a partial mesh topology.
C is incorrect because subjects accessing a hierarchical databasenot an object-oriented databasemust have knowledge of the access path in order to access data. In the
hierarchical database model, records and fields are related in a logical tree structure. Parents can have one child, many children, or no children. The tree structure contains branches,
and each branch has a number of data fields. To access data, the application must know which branch to start with and which route to take through each layer until the data is reached.
D is incorrect because the relationships between data entities provide the framework for organizing data in a relational database. A relational database is composed of twodimensional
tables, and each table contains unique rows, columns, and cells. Each cell contains one data value that represents a specific attribute within a given row. These data
entities are linked by relationships, which provide the framework for organizing the data.