A database is an organized collection of structured and logically related data and information.
Databases play a crucial role in the development of modern-day technology, as they store and manage large amounts of data in an organized manner.
To keep up with the ever-increasing demand for better data management solutions, the rapid pace of technological advancements, and the growth of an application, businesses usually have to change the properties and confines of the database, to enhance performance, security, and scalability.
In this article, we'll explore the concept of database migration and its benefits.
What is Database Migration?
In an application's lifecycle, there might be a need to make changes to the functionality of the application. To track these changes, we employ the services of version control.
Version control is a set of practices and tools to track and manage our application's source files such that any version of the application at different points in the project's history can be retrieved.
But what if our application utilizes an external and explicit dependency like a database? How do we version control this dependency? The answer to this is database migration.
Database migration is a controlled way to manage and track incremental changes within a database.
It helps transform a database from its current state to a new or desired state while preventing the loss of data.
Why do we do Database Migration?
Let's consider a simple example:
Imagine you have an application that stores users' information. To store this data, you would probably need a database that looks like this 👇🏼
| id | name | role |
| 1 | tonie | software developer |
| 2 | victor | technical writer |
Now, due to certain reasons, you need to update the functionality of your application. Maybe the government says that all applications that process and store users' data must process and store their email too.
You quickly go over to your application and make changes to your codebase to accommodate this new rule by adding an extra field to the form and some logic to process it and then you realize that your database cannot store this new field as it was not predefined when creating the database.
Well, you could decide to create an entirely new database and then configure your application to utilize it. But there's a tradeoff here: you will lose all the data that was present in your old database!
So what's the solution to this dilemma? How do you update the boundaries and properties of your database to include this new field without losing your data?
The solution to this is database migration!
Database migration helps you make and track these changes within your database and also updates the properties of your database to reflect them while preserving your existing data.
Back to our example. If a migration tool was used to initialize our database it means that the migration tool is aware of the current state of our database which can be called version one.
Now to update the properties of our database, we would go into our migration script and redefine its properties to include or exclude the fields we want to have (in this case we want to add a new "email" column).
Our migration tool will now go back to our database and apply the changes structurally and logically while keeping our current data. This updated version of our database is now tracked and saved as "version 2". This means we can roll back these changes at any point during our application's life cycle.
Our updated database should look like this after the migration has taken place and we've added a new user
| id | name | role | |
| 1 | tonie | software developer | null |
| 2 | victor | technical writer | null |
| 3 | chisom | new user | chisom@newuser.com |
As we can see we have added a new user to the database with all the current fields and our old users that have not yet provided this information (the email) have been assigned a value of null.
Now they can be prompted to provide this information which will be used to populate their respective fields.
Benefits of Database Migration
As we have seen earlier, database migration is a very beneficial tool for software developers working with databases.
Here are some benefits of database migration
Preservation of data.
Creating a dependable data backup.
Increased efficiency within an application.
Reduced downtime.
Integration with modern technologies.
In conclusion, database migration is a critical process that enables businesses to enhance their data management capabilities by keeping track of the changes in their database.
It can help organizations achieve better performance, security, scalability, and flexibility while minimizing costs and downtime. However, the migration process can be complex, and several factors need to be considered to ensure a successful outcome.
It's essential to choose the right approach, plan the migration carefully, and perform thorough testing to minimize risks and avoid data loss.
By understanding database migration and its benefits, businesses can make smart decisions that help them achieve their data management goals and maintain a competitive advantage.