Difference Between Redis and RDBMS

Databases are organized collections of structured data or information stored in computers electronically. Retrieving any data directly from a database can take a lot of time.

Instead, a quicker alternative would be to access this data directly from RAM (Random Access Memory). This is where software such as Redis and RDBMS come into play.

They provide any data queried in much less time than a database would.

Redis vs RDBMS

The main difference between Redis and RDBMS is that while the Redis database stores all its data in its primary memory, making it easier to access, the RDBMS database stores all its data in its secondary memory, making it more difficult to access.

Redis vs RDBMS

REDIS (REmote DIctionary Server) is a NoSQL database. It is open-source software that is primarily used as a cache for applications and as a response database.

Redis delivers unparalleled speed, reliability, and performance since its data is stored in primary memory and not on any external hard drives.

RDBMS (Relational Database Management System) consists of data points related to one another and stores and provides access to them.

Data in relational databases are organized in tables using the relational model, which is intuitive and straightforward.

Comparison Table Between Redis and RDBMS

Parameters of ComparisonRedisRDBMS
DefinitionRedis is a free and open-source cache database.An RDBMS is simply a program that manages databases.
StorageIn Redis, everything is stored in primary memory. 
With RDBMS, everything is stored in secondary memory.
SpeedSince Redis stores data in primary memory, Read and Write operations are extremely fast.
Because RDBMS stores data in secondary memory, Read and Write operations are slow.
Primary memory is significantly more expensive. Thus, storing data using Redis is costly too.
Secondary memory is relatively cheaper. Thus, storing data is cheap too. 
Storage capacity
Due to the small primary memory, Redis cannot store large files or binary data.
The secondary memory is abundantly large, so RDBMS can handle such files easily.
Type of data stored
Redis is usually used for storing very small textual data that needs to be accessed, modified, and inserted quickly. You will receive an error if you try to write bulk data beyond the memory available.
An RDBMS can hold large amounts of data that are less frequently utilized and are not expected to operate at high speeds.

What is Redis?

Redis is short for REmote DIctionary Server. It is open-source software. A NoSQL database, it uses the key-value storage principle.

This is why Redis is often used as a cache directory to retrieve data as quickly as possible for web applications. Because Redis stores data in the primary memory, its users can access the data at unprecedented speeds.

The reliability and performance of Redis have earned it the trust of millions of users.

Using an external database to retrieve data directly from a web application can be very slow. Most of this slowness is caused by high traffic volumes.

Users may find it extremely frustrating when the application’s performance is negatively affected. Keeping the necessary data as close to the system as possible would make things much easier.

Redis is designed for this purpose. It keeps the data in the primary memory, which makes accessing this data very convenient and improves the performance.

There are several differences between Redis and other NoSQL databases, such as MongoDB and PostgreSQL. Redis is designed primarily to improve the performance of applications.

As opposed to external hard drives or SSDs, Redis stores its data in the primary memory of the server. Therefore, client wait times are significantly reduced.

Furthermore, it is possible to fill its database with new data previously unavailable in its database, despite the fact that it is unable to store a large amount of data.

What is RDBMS?

RDBMS is used for retrieval and access of data that are linked to each other. The relational model, one of the simplest ways to represent data in tables, is the basis of relational databases.

According to a relational database, each row in a table is a record containing a unique key.

It is easy to determine relationships between data points because each column of the table contains attributes of the data, and every record contains a value for every attribute.   

A relational model is made up of logical data structures (like data tables, indexes, views), and physical data structures. Physical and logical storage is distinct.

The difference between physical and logical data storage also applies to database operations, which are clearly defined activities that enable applications to manipulate data and structures within a database.

Therefore, physical and logical databases can be accessed and modified separately. 

An organization of any size can use the simple yet powerful relational model for a wide range of information needs.

Many organizations use relational databases to manage large amounts of mission-critical information, track inventories, process transactions, and manage customer information.

Relational databases are suitable for any information need where data points should be linked.

Main Differences Between Redis and RDBMS

  1. In Redis, everything is stored in the primary memory, whereas in an RDBMS, it is stored in the secondary memory.
  2. RDBMS cannot access data as fast as Redis.
  3. The cost of primary memory is higher than that of secondary memory. This makes Redis a cheaper alternative to RDBMS for storing data.
  4. Secondary memory is larger than primary memory. Therefore, Redis can store fewer data.
  5. The data stored in Redis can be easily accessed and is small. Whereas RDBMS stores large amounts of data that are rarely accessed.
Difference Between Redis and RDBMS


The process of retrieving data directly from a database can be tedious. A fast-paced technological environment makes it undesirable to have to wait for data retrieval.

The user would appreciate it if this needed information could be provided to him as quickly as possible. Redis and RDBMS would be useful in this case.

Instead of directly querying the databases, these services access the data in an intermediate cache and then retrieve it directly from RAM (or Random Access Memory) on the server performing the query.

Despite the pros and cons of both services, they simplify and speed up our lives considerably.


  1. https://link.springer.com/chapter/10.1007/978-1-4842-2976-7_7
Search for "Ask Any Difference" on Google. Rate this post!
[Total: 0]
One request?

I’ve put so much effort writing this blog post to provide value to you. It’ll be very helpful for me, if you consider sharing it on social media or with your friends/family. SHARING IS ♥️