Should You Learn Amazon RDS or DynamoDB?

Modern-day application stores a lot of information and data to understand customer expectations and deliver personalized solutions. All these pieces of information are stored in databases. Now, developers can leverage data from databases using various methods. What confuses them most is the choice of service or method they need to pick in order to manage their database. They can pick either relational or non-relational methods of managing databases. In terms of tools and services, there exists a plethora of services in the market that developers can pick. All these options are enough to make a developer trip over! In this article, I have tried to address whether one should pick Amazon RDS or Dynamo DB. But before we can proceed to that, let’s have a quick look at the difference between relational and non-relational databases. 

Understanding Relational vs. Non-Relational Databases

There are two different approaches to constructing a database — relational and non-relational databases.

A relational database leverages SQL, a.k.a structured query language, to interact with the database. Such databases always have some sort of relational and tabular data with underlying rules to maintain consistency and integrity. SQL databases can be scaled vertically by increasing the hardware capability of the server, like CPU, RAM, storage, etc.

A non-relational database is a class of database management systems that don’t rely on SQL. Instead, they adapt to dynamic schemas and unstructured data. If your data sets keep on changing frequently, a non-relational database is the best way to deal with it. Unlike SQL databases, non-relational databases can be scaled horizontally. This makes scalability a lot easier.

What Is Amazon DynamoDB?

Amazon DynamoDB is a fully managed NoSQL database service from AWS. It is designed to automatically scale tables to adjust for capacity and maintain high performance with zero administration.

• No more provisioning, patching, or managing servers for scalability and availability
• No more installing, operating, or maintaining database software
• Built-in fault tolerance, security, backup and restore, automated multi-Region replication, and more.

AWS does most of the heavy lifting to support DynamoDB. However, you need to be mindful when modeling data in DynamoDB. 

What Is Amazon RDS?

Amazon RDS(Relational Database Service) is a service offered by AWS to operate and scale SQL-based databases on AWS. It helps with relational database management tasks like — migration, backup, recovery, and patching. Amazon RDS is also responsible for the deployment and maintenance of regional databases. There are six SQL-based database engine options provided by AWS:

• Amazon Aurora
• MySQL
• MariaDB
• PostgreSQL
• Oracle
• Microsoft SQL Server

Performance Comparison: DynamoDB vs. Amazon RDS

What’s good is learning a new skill if it’s not in demand or performance oriented. 

DynamoDB is well known in terms of performance, as it can cope with more than 10 trillion requests within a single day. At its peak, it is easily capable of handling 20 million requests per second. Apart from the high-performance SSD, the DynamoDB Accelerator (DAX) also contributes to minimizing latency. You can reduce your reading speeds by using DAX from milliseconds to microseconds! Irrespective of the table size, if you use proper indexing and partitioning, DynamoDB is a high-performing database.    

Amazon RDS is the high-performance choice for developing OLTP(Online Transactions Processes) applications. It is also considered a cost-effective solution for general-purpose use. Amazon RDS delivers 3 IOPS per provisioned GB for a general-purpose solution that can be scaled up to 3000 IOPS. A performance-oriented RDS instance can deliver up to 40,000 IOPS per database instance. The IOPS rate is maintained throughout the lifetime of the database instance. 

When To Use Dynamo DB?

Amazon DynamoDB is ideal for low-scale operations due to its simplicity. But it also shines at operating on an ultra-high scale, as demanded by Amazon.com. It powers many other powerful applications, including Snapchat, Zoom, Dropbox, and more. You should consider using DynamoDB for:

• Key-value or simple queries
• When high-performance reads and writes are required
• Auto-sharding
• Low latency applications
• High durability
• When no tuning is required
• When there are no size or throughput limits
• When you have scalability issues with other traditional database systems
• Online transaction processing (OLTP) workloads
• Mission-critical applications that must be highly available all the time without manual intervention

When Not To Use DynamoDB

Amazon DynamoDB may not be suitable for:

• Multi-item/row or cross-table transactions
• Complex queries and joins
• Real-time Analytics on historical data
• Services that need ad hoc query access
• Online analytical processing (OLAP) or data warehouse implementations
• Binary large object (BLOB) storage. However, blobs can be stored in Amazon S3 and its object pointers in a DynamoDB table.

When To Use Amazon RDS?

As discussed above, Amazon RDS is based on some sort of relational or structured data. For enterprise applications that rely on relational databases due to the nature of data storage, we need to use Amazon RDS.  It is useful for 

• Building traditional applications
• CRM and e-commerce solutions
• When you want an automatic scaling solution
• Good for OLAP (Online analytical processes) applications

When Not To Use Amazon RDS?

Amazon RDS may not be suitable when:

• You need to restore an individual database. This is because the process is utterly complex and eliminates the biggest benefit of using a PaaS service. 
• If you are considering patching to the latest edition. This is because although Amazon uses hot patching, it doesn’t always have the current CU available for you. 
• If you care about licensing, consider sticking with Azure services. As AWS doesn’t own the source code, you don’t have the option of running the developer edition for non-production workloads.

Million Dollar Question

After the in-depth comparison between Amazon RDS and DynamoDB, it all narrows down to the million-dollar question — “which one should you learn?” Both of them have developer-oriented pros and cons. As far as learning is concerned, learning Amazon RDS makes more sense than DynamoDB. This is because, in most cases, relational databases are capable enough of solving the problem. 

But, if you ask me, don’t make a choice when you don’t have to! Learning both of them will give you a better edge in the future. Being a developer doesn't mean we solve problems with the knowledge/skills that we have, but we pick the best solution to deal with the problem at hand! If you have any queries regarding the same, feel free to reach out to me in the comments below.