What Is a Transaction?

Imagine we are buying our favorite gadget from an online store. When we click “Place Order,” several things need to happen seamlessly: the store needs to check if the item is in stock, reduce the stock count, process our payment, and then record our order. What if the payment fails after the stock has been reduced? Or what if the system crashes right after taking our money but before recording the order? This is where the concept of a transaction becomes incredibly important. It ensures that all these steps are treated as a single, indivisible operation. Either everything happens successfully, or nothing does, keeping the database consistent and reliable.

In this lesson, we’ll dive into the world of transactions. By the end of this lesson, we will be able to:

• Understand what a database transaction is.

• Recognize the importance of transactions in maintaining data integrity.

• Identify real-world scenarios where transactions are crucial.

• Get a preliminary understanding of how transactions are managed.

Let’s get started on understanding this fundamental concept!

What is a transaction?

In the world of databases, a transaction is a sequence of one or more database operations (like SELECT, INSERT, UPDATE, or DELETE) that are executed as a single logical unit of work. Think of it like a package deal. For the transaction to be considered successful, all operations within it must complete successfully. If any single operation within that package fails, then the entire transaction fails, and any changes made by the preceding operations in that same transaction are undone, returning the database to the state it was in before ...