Language to find objects and retrieve data from the database.Ībility to use an object-oriented programming language for data manipulation.ĪCID transactions guarantee all transactions are complete without conflicting changes.Ĭreates a partial replica of the database. Most contain the following features: Feature There are different kinds of implementations of object databases. An established connection to the internet represents an abstraction, whereas the various types of connections represent different implementations of the abstraction. However, the connection type is irrelevant. A web browser needs an internet connection. Abstraction helps reduce the complexity of modeled data and allows reusability.įor example, there are different ways for a computer to connect to the network. The process selects vital information while unnecessary information stays hidden. AbstractionĪbstraction is the procedure of representing only the essential data features for the needed functionality. A class encapsulates all the car information into one entity, where some elements are modifiable while some are not. You can change the color of a car, yet the model or make are examples of properties that cannot change. Classes interact with each other through methods without the need to know how particular methods work.Īs an example, a car has descriptive characteristics and actions. Through this process, pieces of information and details of how an object works are hidden, resulting in data and function security. EncapsulationĮncapsulation is the ability to group data and mechanisms into a single object to provide access protection. Both child classes inherit information from the parent class and extend the parent class with new information depending on the vehicle type. The existing class is the parent class, while the child class extends the parent.įor example, a parent class called Vehicle will have child classes Car and Bike.
#Hierarchical database management system pdf plus
Defining new types inherits all the existing class fields and methods plus further extends them.
#Hierarchical database management system pdf code
Inheritance creates a hierarchical relationship between related classes while making parts of code reusable. The defined action is polymorphic - the result changes depending on which vehicle performs.
In this example, the action break is a polymorphism. Both a car and a bike are able to break, but the mechanism is different. This ability allows the same program code to work with different data types. Polymorphism is the capability of an object to take multiple forms.
These four attributes describe the critical characteristics of object-oriented management systems. The four main ideas of object-oriented programming are: Object-oriented databases closely relate to object-oriented programming concepts. This approach unifies attributes and behaviors of data into one entity. An object-oriented management system provides supported functionality catered to object-oriented programming where complex objects are central. These characteristics make object databases suitable for projects with complex data which require an object-oriented approach to programming.
0 kommentar(er)
