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Types of Databases: Explained with Examples

Databases are crucial for managing data in today’s digital world. They store, organise, and enable retrieval of data. Databases are the backbone of most web-based applications, such as financial systems.

This blog will cover different types of databases, their features, and where they are used. Understanding these categories will help you in selecting an appropriate database for your needs. Let’s explore various types of databases to see how they ensure efficient management and security of data.

What is a Database?

A database is a structured collection of data that is stored and managed electronically. It allows users to store, retrieve, and manipulate data efficiently. The databases must be capable of managing huge amounts of records plus other functions like querying, inserting new values, or updating existing ones.

Tables form the basis for any database system. Tables are composed of rows and columns that represent records and fields, respectively. This type of structure facilitates easy storage and retrieval of information quickly with greater accuracy. For instance, in a customer database, each row could be an individual customer, while columns may include fields such as name, address, phone number, email, etc.

There are various databases available, all designed to suit their respective purposes. Some databases focus on speed optimization, while others handle complicated relationships between sets. The choice of the database depends on the requirements of the application and the nature of the data being managed.

Databases come in many forms depending on the nature of the data stored inside them as well as what they aim to achieve when put into operation. The variation between these groups shall help one decide which would best fit their requirements. In this section, we will discuss common types, including those that have been widely used in industries today, along with their advantages, disadvantages, and areas where they are typically employed.

Relational Databases

The relational database is an example of a database that organises its data into tables. Each table row represents a record, while the column signifies the field for that particular record. These tables are exposed to structured query language (SQL), which supports more complex queries and ensures data integrity by creating relationships across them.

Pros:

• Easy to understand and use due to the structured format.
• Strong consistency and integrity.
• Supports complex queries and transactions.

Cons:

• It can become slow with very large datasets.
• Less flexible with unstructured data.
• Requires a fixed schema.

Common Use Cases:

• Financial systems.
• Customer relationship management (CRM) systems.
• Inventory management.

NoSQL Databases

NoSQL databases are designed to handle unstructured or semi-structured data. They offer flexible schema designs and can scale horizontally across many servers. NoSQL databases are categorised into several types:

• Document-oriented database
• Key-value database
• Column-family database
• Graph database

Pros:

• Highly scalable and flexible.
• Can handle large volumes of unstructured data.
• Fast data retrieval for specific use cases.

Cons:

• Lack of standardisation.
• May sacrifice consistency for scalability.
• It can be complex to manage without proper expertise.

Common Use Cases:

• Real-time web applications.
• Big data analytics.
• Content management systems.

Hierarchical Databases

Hierarchical databases organise data in a tree-like structure, with parent-child relationships between data elements. Each parent can have multiple children, but each child has only one parent. This type of database is efficient for certain types of data retrieval and hierarchical relationships.

Pros:

• Simple and straightforward data model.
• Efficient for hierarchical data retrieval.
• Fast access due to tree structure.

Cons:

• Limited flexibility for complex relationships.
• Data redundancy is common.
• Difficult to reorganise the database structure.

Common Use Cases:

• Organisational charts.
• File systems.
• XML data storage.

Network Databases

Network databases use a flexible model resembling a graph, where each record can have multiple parent and child records. This model allows for more complex relationships between data compared to hierarchical databases. Network databases use structures called sets to establish many-to-many relationships between records.

Pros:

• Handles complex relationships efficiently.
• Reduces data redundancy by allowing multiple parent-child connections.
• More flexible than hierarchical databases.

Cons:

• It can be complex to design and manage.
• Requires a thorough understanding of the network model.
• Difficult to maintain and modify.

Common Use Cases:

• Telecommunications and network systems.
• Geographic information systems (GIS).
• Complex data relationships in various industries.

Object-Oriented Databases

Object-oriented databases integrate object-oriented programming principles with database technology. They store data as objects, similar to how data is represented in object-oriented programming languages. Each object contains data and methods, encapsulating both state and behaviour, which allows for complex data models and relationships.

Pros:

• Seamless integration with object-oriented programming languages.
• Supports complex data types and relationships.
• Enhances code reusability and maintainability.

Cons:

• It can be slower for simple queries compared to relational databases.
• Steeper learning curve for those unfamiliar with object-oriented concepts.
• Less mature and widely used compared to relational databases.

Common Use Cases:

• Applications requiring complex data models, such as CAD/CAM systems.
• Real-time systems and simulations.
• Multimedia applications.

Cloud Databases

Cloud databases are databases that run on cloud computing platforms, offering scalability, flexibility, and managed services. They can be relational or NoSQL and are accessed over the internet. Cloud databases provide high availability, disaster recovery, and automated backups, making them a popular choice for modern applications.

Pros:

• Highly scalable and flexible.
• Reduces infrastructure and maintenance costs.
• Provides high availability and disaster recovery.

Cons:

• Dependence on internet connectivity.
• Potential security concerns with data stored off-premises.
• Ongoing operational costs.

Common Use Cases:

• Web and mobile applications.
• Data warehousing and analytics.
• IoT data management.

Centralised Database

A centralised database is a single database located and maintained in one location, typically a central server or data centre. It provides a consistent and unified data source for users and applications. Centralised databases are easier to manage and secure but can become a bottleneck for performance and scalability.

Pros:

• Easier to manage and maintain.
• Enhanced data security and integrity.
• Simplified data consistency.

Cons:

• Potential performance bottlenecks.
• Single point of failure.
• Limited scalability compared to distributed databases.

Common Use Cases:

• Enterprise resource planning (ERP) systems.
• Customer relationship management (CRM) systems.
• Centralised data repositories for large organisations.

Operational Database

Operational databases, also known as online transaction processing (OLTP) databases, are designed to handle real-time data operations and transactions. They support day-to-day business activities by processing a large number of short online transactions. These databases prioritise fast query processing, data integrity, and concurrent access.

Pros:

• Optimised for fast transaction processing.
• Ensures data integrity and consistency.
• Supports concurrent access by multiple users.

Cons:

• It is not ideal for complex queries or large analytical workloads.
• Requires regular maintenance and tuning.
• It can be resource-intensive.

Common Use Cases:

• Banking and financial transactions.
• Order processing and inventory management.
• Retail point-of-sale (POS) systems.

Conclusion

The decision of which database to select for your application is a vital one, as each type has its own peculiarities. It is important to know how good or bad they could be and some examples of where they can be applied in order to make better decisions.

The right choice of database greatly affects application performance and scalability. For example, if you have structured data, then use RDBMS. Otherwise, if there is no need for any structure at all, go with a NoSQL database system. This allows for achieving goals more effectively because such databases are made to be simple and work in the desired manner.