What is data?

In the context of databases, data refers to all of the individual things that are saved in a database, either individually or collectively. The majority of data in a database is saved in database tables, which are structured into columns that specify the data types that can be stored. A collection of unique little units of information is referred to as data. It can take many different forms, including text, numbers, media, bytes, and so on. Data is information that can be converted into a format for efficient movement and processing in computing.

What is a database?

A database is a collection of data that has been arranged so that it can be readily accessed and controlled. The database's principal purpose is to store, retrieve, and manage a significant amount of data. Databases are used to manage a large number of dynamic websites on the Internet today. Consider a model that checks the availability of hotel rooms. It's an example of a database-driven dynamic webpage.

Types of database

There are many different types of databases according to the requirement of an individual and organization. The different types of databases are:

1. Centralized database

A centralized database is one that is kept in one place, such as a mainframe computer. It's a database that stores information in a centralized database system. It allows users to access stored data from a variety of locations using a variety of applications. It is only maintained and edited from that place, and it is normally accessed over a LAN or WAN connection. Organizations such as colleges, enterprises, and banks use the consolidated database.

Advantages

• A centralised database is used to manage data redundancy. All of the data is kept in one place and cannot be distributed to other locations. As a result, it's much easier to ensure that no data is duplicated.
• The cost of a centralised database is lower than that of other databases.

Disadvantages

• If the centralised server fails for any reason, the entire database will be lost.
• When all data is stored in one location and multiple users access it at the same time, it can cause consistency issues.

2. Distributive database

A distributed database system is made up of multiple sites with no physical components in common. This may be necessary if a database needs to be viewed by a large number of people all over the world. It must be administered in such a way that it appears to users as a single database. Communication links connect these database systems together. End-users can readily access data with the use of such links.

Advantages

• The database is easier to extend because it is already scattered across numerous systems, and adding a system is not difficult.
• The data in the distributed database can be organised according to different levels of transparency.

Disadvantages

• As the distributed database is dispersed across several sites, it is difficult to ensure that a user receives a consistent view of the database.
• This database is more expensive to maintain since it is more sophisticated.

3. Personal database

A personal database is used to hold information that is often utilized, unique, or personalized. This allows for quicker access to specific information that can be used across various research and projects.

Advantages

• Data can be processed more quickly and reliably if it is stored on a local computer.
• The authorisation of data kept on a personal computer does not necessitate any particular security arrangements.

Disadvantages

• In a personal database management system, storage capacity is less.
• The data is kept locally on only one system and is not accessible from any other systems.

4. Network database

A network database management system (network DBMS) uses a network data model to allow each record to be linked to several primary and secondary records. It allows each record to have several children and parent nodes, forming a generalized network structure, unlike a hierarchical database.

Advantages

• The many-to-many interaction is the main advantage of the network DBMS paradigm.
• Several human organisational actions necessitate one entity having many upward links to other entities.

Disadvantages

• Network databases, unlike relational databases, do not include structures that resolve many-to-many relationships between instances, or records, of an entity.

5. Hierarchical database

A hierarchical database is defined as a structure that stores data in a parent-child relationship pattern. This data structure arranges data in a tree-like or hierarchical manner. In a tree, each child in a hierarchical database can only have one parent. On the other hand, one parent record can contain the records of multiple children.

Advantages

• The relationships between the levels are simple and rely on hierarchical structure (parents or child nodes).
• When the database contains a big number of 1:n relationships and the user requires a large number of transactions, it is particularly efficient.

Disadvantages

• While it is simple and straightforward to design, it is rather tough to put into action.
• Any modifications to the database structure necessitate changes to the entire application programme that connects to the database.

6. Relational database

This database uses the relational data model, which stores data in the form of rows (tuples) and columns (attributes), which are combined to make a table (relation). A relational database employs SQL for data storage, manipulation, and maintenance. In 1970, E.F. Codd invented the database. Each table in the database has a key that distinguishes the data from that of other tables. MySQL, Microsoft SQL Server, Oracle, and other RDBMS are examples.

Advantages

• Because a relational database has multiple tables, specific tables can be declared confidential. Users are only permitted to work on that specific tables.
• A relational database model is much simpler than other forms of network structures.

Disadvantages

• The enabling cost of a relational database is high.
• The amount of tables in a relational database always affects its performance. The response time for queries will be slower as the number of tables increases.

7. Cloud database

A cloud database is a database service that is produced and accessible via the internet. It performs many of the same tasks as a traditional database, but with the extra benefit of cloud computing flexibility.

Advantages

• Cloud databases, in particular, are extremely efficient because their potential to expand is unrestricted.
• As your company's mobile workforce grows, cloud platforms' flexibility to be accessed and used from a variety of remote devices can be a big benefit.

Disadvantages

• The initial cost of database hosting services may be less than the cost of increasing your company's existing servers.
• The database is susceptible to security attacks as cloud infrastructure is used.

8. Non-SQL database

Non-SQL is a database that may be used to store a wide variety of data sets. It is not a relational database because it holds data in a variety of formats, not only tabular. It was created in response to a rise in the need for modern applications.

Advantages

• Unlike relational databases, which can only store data in an organised format, NoSQL databases can store and mix any sort of data, both structured and unstructured.

Disadvantages

• No standard exists that defines the rules and functions of NoSQL databases.

Related topics

• Relational databases/RDBMS
• Graph database
• NoSQL database

Context and applications

This topic is significant in the professional exam for both graduate and postgraduate courses, especially for-

• Bachelor of Technology in Computer Science
• Bachelor of Technology in Information Technology
• Master of Technology and Master of Computer Application

Practice problems

Q1. RDBMS stands for _____________

1. Relative Database Management System
2. Regional Database Management System
3. Relational Database Management System
4. None of the above

Correct Ans- 3. Relational Database Management System

Explanation- RDBMS stands for Relational DataBase Management Systems. It's an application that lets us build, remove, and update relational databases.

Q2. In Distributive Database, data is stored in the form of _____________

1. Class
2. Objects
3. Methods
4. None of the above

Correct Ans- 2. Objects

Explanation- An object is used to represent an entity, and objects are maintained in memory. Fields, properties, and methods are all members of objects. Objects have a life cycle that includes the creation, usage, and destruction of objects.

Q3. A/An __________ is a collection of data stored in a systematic manner.

1. Index
2. Objects
3. Database
4. None of the above

Correct Ans- 3. Database

Explanation- A database is a shared, systematic collection of logically connected data that is saved to satisfy the needs of various users within an organization and can be easily accessed, controlled, and updated.

Q4. MySQL is an example of

1. Graph database
2. Relational database
3. Hierarchical database
4. Network database

Correct Ans- 2. Relational database

Explanation- A Relational Database Management System (RDBMS) is a database management system for a relational system (RDBMS). An RDBMS is anything like MySQL or mSQL.

Q5. SQL stands for _______________________

1. Structured Query Language
2. Structured Question Language
3. Simplified Query Language
4. None of the above

Correct Ans- 1. Structured Query Language

Explanation- SQL stands for Structured Query Language. SQL is a language for interacting with databases. It is the standard language for relational database management systems, according to ANSI (American National Standards Institute).