Source: PlanetScale Blog
Transactions are fundamental to how SQL databases work. Trillions of transactions execute every single day, across the thousands of applications that rely on SQL databases.
A transaction is a sequence of actions that we want to perform on a database as a single, atomic…
Overview This chapter from Designing Data‑Intensive Applications explores different database models and strategies for structuring application data. Understand...
Problem Description The table Transactions has the following columns: - id primary key - country - state enumeration: 'approved' or 'declined' - amount - trans...
Problem Overview The task is to identify the customer number that has placed the largest quantity of orders. The Orders table contains two identifier columns:...
When interviewing for backend or data roles, you’ll often see the classic problem: “Find the second highest salary from the Employee table. If there is no secon...
