Redis: A Comparison with Other Databases (Bite-size Article)
Tags: redis, database, mongodb, rdbms
Published: 2023-11-05 00:07:50

#Introduction

- [Session Management Basics with Redis
](https://dev.to/koshirok096/session-management-basics-with-redis-2o2e)
- [Redis : Starter Setup, Learn Basics for Beginners (Bite-size Article)](https://dev.to/koshirok096/redis-starter-setup-learn-basics-for-beginners-bite-size-article-3ai5)

---

Hello everyone. In this article, I will write about Redis again! The topic is the differences between Redis and other type of databases. I will briefly summarize the features of Redis, the differences in specifications with other types of databases, and their respective advantages and disadvantages.

First, let's start with the features and advantages and disadvantages of Redis.

#Redis

Redis is a fast **key-value database** that stores data in memory, providing quick access for users ([See this article](https://dev.to/koshirok096/session-management-basics-with-redis-2o2e) for more information).


Redis, as a versatile **NoSQL** database, excels in various scenarios. Its primary applications include efficient **caching**, effective **session management**, and real-time data processing, especially in Pub/Sub-based scenarios for handling data instantaneously.

The main strengths and limitations are as follows.

##Strengths of Redis
- Swift Read/Write Operations: Redis leverages **in-memory storage**, enabling lightning-fast read and write operations.
- Diverse Data Structures: Supporting various data structures like `strings`, `hashes`, `lists`, `sets`, and `sorted` sets provides flexibility in data storage.
- Session Management and Event-Driven Abilities: With support for Pub/Sub and transactions, Redis facilitates efficient **session** handling and real-time event processing.

##Limitations of Redis
- Storage Capacity Constraints: Dependency on memory size leads to limitations in storing large volumes of data persistently.
- Limited Complex Querying Abilities: Compared to some other NoSQL databases, Redis lacks advanced querying features.

The strength of Redis is its simplicity, user-friendliness, and great performance. The drawback of Redis, on the other hand, is its difficulty in managing complex data with the same level of flexibility as an SQL database.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/f3vfpw75cvrla77pt6ev.png)

#Comparing Redis with Other Databases - Differences from RDBMS

The differences between Redis and a **RDBMS** (relational database management system) are clear in terms of data structure, transaction processing, and performance.

##Data Structure:
- <u>Redis</u>: Redis stores data using **key-value pairs** and offers extreme flexibility with support for various data types (`strings`, `hashes`, `lists`, `sets`, etc.). It has a loose schema and allows dynamic addition of new data types.
- <u>RDBMS</u>: Relational databases structure data into **tables**, **rows**, and **columns**. They require a strict schema design before creating tables.

##Transaction Handling:
- <u>Redis</u>: Redis supports transaction handling but <u>doesn’t fully guarantee ACID (Atomicity, Consistency, Isolation, Durability) properties</u>. Its level of consistency is selective, and it might have limitations in complex transaction handling.
- <u>RDBMS</u>: RDBMS provides <u>complete support for ACID transactions</u>, ensuring data consistency, transaction rollbacks, and more.

##Performance:
- <u>Redis</u>: Being an in-memory database, Redis retains data in memory, enabling **high-speed read and write operations**. This makes it suitable for real-time data processing and caching purposes.
- <u>RDBMS</u>: Relational databases commonly store data on disks, which may lead to delays due to disk access. Performance depends on query and index optimization.

Redis is suitable for its flexible data structures, high-speed performance, and specific use cases. However, if data persistence or strict transaction control is required, an RDBMS might be more suitable.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/rqjc86saw6huk7l6kl9k.png)


#Comparing Redis with Other Databases - Differences from Other NoSQLs Databases

As a widely recognized NoSQL database, **MongoDB** stands as a leading option. There are other NoSQL databases like **Amazon DynamoDB**, **Cassandra**, **Couchbase**, and more. 

There are many NoSQL databases to consider, making it hard to compare each with Redis. So, in this article, let's focus on comparing MongoDB with Redis.

If you are interested in comparing Redis with other NoSQL databases that you are using, please research and compare them yourself (I'm sorry!)

##Differences:

###Data Model:
- <u>Redis</u>: **Key-value pairs**, supporting diverse data structures (`strings`, `lists`, `sets`, etc).
- <u>MongoDB</u>: **Document-oriented**, employing flexible **JSON-style documents**

###Performance:
- <u>Redis</u>: **In-memory database** ensuring fast read/write access.
- <u>MongoDB</u>: **Persists data on disk**, and its performance is impacted by data volume and query complexity.

###Query Language:
- <u>Redis</u>: Supports simpler queries, but with constraints compared to MongoDB.
- <u>MongoDB</u>: Employs a robust query language enabling complex queries and aggregations.

###Advantages:
- <u>Redis</u>: Ideal for real-time data processing with **rapid read/write access**. Excellent for **caching**, **session management**, and offers high scalability. Provides a flexible data model, efficiently managing diverse data structures.
- <u>MongoDB</u>: Suited for projects with **frequently changing data** due to its flexible data schema. Capable of handling complex queries and aggregations with large datasets. Ensures data persistence, offering high data durability.

###Disadvantages:
- <u>Redis</u>:
Limited by memory capacity, and **data is not persistent** (may be lost upon shutdown).
<u>**Not suitable for complex queries or transaction handling**</u>.
- <u>MongoDB</u>:
Disk-based data persistence can sometimes impact read/write speed.
Schema-less data model poses challenges for data quality management and requires appropriate design.

Selection depends on project requirements, with Redis and MongoDB offering distinct advantages and limitations. Redis is generally preferred for real-time data processing and caching, while MongoDB is suitable for flexible schema requirements and complex queries.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/fdtmdetz7ztpqlg1h2uu.png)

#Conclusion

In this article, I've provided a simple and brief comparison of Redis and other databases. I hope this article has been helpful to you!

Thank you for reading :)