Inheritance creates a hierarchical relationship between related classes while making parts of code reusable. Defining new types inherits all the existing class fields and methods plus further extends them. The existing class is the parent class, while the child class extends the parent. For example, a parent class called Vehicle will have child classes Car and Bike. Both child classes inherit information from the parent class and extend the parent class with new information depending on the vehicle type.
Encapsulation is the ability to group data and mechanisms into a single object to provide access protection. Through this process, pieces of information and details of how an object works are hidden , resulting in data and function security. Classes interact with each other through methods without the need to know how particular methods work. As an example, a car has descriptive characteristics and actions. You can change the color of a car, yet the model or make are examples of properties that cannot change.
A class encapsulates all the car information into one entity, where some elements are modifiable while some are not. Abstraction is the procedure of representing only the essential data features for the needed functionality. The process selects vital information while unnecessary information stays hidden. Abstraction helps reduce the complexity of modeled data and allows reusability. For example, there are different ways for a computer to connect to the network.
A web browser needs an internet connection. However, the connection type is irrelevant. An established connection to the internet represents an abstraction , whereas the various types of connections represent different implementations of the abstraction. There are different kinds of implementations of object databases.
Most contain the following features:. Developers who write applications in Smalltalk adapt easily to this database. There are multiple options for licensing depending on the project size. Note: Learn all about how database servers work to find out how they can be an asset to you. ObjectDB includes all basic data types in Java, user-defined classes, and standard Java collections.
Every object has a unique ID. The number of elements is limited only by the maximum database size TB. Objects have members such as fields, properties, and methods. Objects also have a life cycle that includes the creation of an object, use of an object, and deletion of an object. OOP has key characteristics, encapsulation, inheritance, and polymorphism. Object databases are commonly used in applications that require high performance, calculations, and faster results.
Imagine creating objects in your program and saving them as it is in a database and reading back from the database. In a typical relational database, the program data is stored in rows and columns.
To store and read that data and convert it into program objects in memory requires reading data, loading data into objects, and storing it in memory. Imagine creating a class in your program and saving it as it is in a database, reading back and start using it again. Object databases bring permanent persistent to objects. Objects can be stored in persistent storage forever. In typical RDBMS, there is a layer of object-relational mapping that maps database schemas with objects in code.
Hence faster data access and better performance. Some object database can be used in multiple languages. It is difficult to find object DB developers. Not many programming language support object databases. Object databases do not have a standard. Object databases are difficult to learn for non-programmers. Popular Object Databases Here is a list of some of the popular object databases and their features. The system is accompanied by a highly configurable graphical user interface that builds upon the logic-based features of the ConceptBase.
There is also a pre-configured virtual appliance that contains the executable system plus its sources plus the tools to compile them. Relational database management systems RDBMS work with tables, with each row in the table representing a record.
The columns in a row represent the attributes of an individual record. Data values stored in relational databases are atomic and primitive. By primitive, we mean that they are types like characters, text strings, numbers, and hashes.
There are no tables, no rows, no columns, no foreign keys. There are only objects. Associations between objects in an OOD can also be established and persist, which can lead to powerful and fast querying of data across complex relationships. At times, relationships between documents might be the preferred approach.
For example, you can think of a BlogPost document that has associations with multiple Comment documents and Like documents. At other times, relationships can be embedded directly into a document. In this case, you can imagine a BlogPost document with a Comments attribute which is an array of text strings and usernames, and then another Likes attribute which is an array of usernames and timestamps.
Document databases provide flexible structures that scale well horizontally. With all of their complex associations to other objects, and because mplex data objects persist in an OOD, the most significant advantage of the OOD over RDBMS is the ability to query across these complex relationships very quickly. As another example, we might think back to our task object instance, which cannot be stored as-is in MySQL.
It needs first to be decomposed into its attributes to be stored in the table as a row with columns. The reverse process will involve retrieval and composition. Not so with object-oriented or document databases. Have an object? Store the whole thing in the database. Designing and optimizing a database system for these kinds of complexities, however, also has its trade-offs. Additionally, while users of RDBMS can enjoy a standard query language SQL , users of object-oriented database systems may not have widely adopted standards at their disposal.
For the most part, each flavor of OOD is coupled tightly to an object-oriented programming language, and querying syntax is very language-dependent. But the community is fast-growing and likely to make up for lost time. If your application is built with an object-oriented language, then there is likely an OOD or document DB that couples well with your language.
MongoDB Atlas is a cloud-based database service for deploying a fully managed instance of MongoDB, based on the foundation of open development with a large community.
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