Explore the fundamentals of databases, including design, management, and querying techniques. Learn about SQL, NoSQL, and best practices for data storage!
Tree traversals are one of the first things we learn in data structures — but they’re often taught only at a surface level: as different ways to “walk” a tree. What’s rarely emphasized is this: A Quick Refresher Given a binary tree, the three primary depth-first traversals are: Traversal Order Preorder Root → Left → … Read more
SQL offers powerful tools like CTEs, Views, and Temporary Tables to simplify complex queries and manage data efficiently. Though they may seem similar, each serves a unique purpose. Understanding their differences helps you write clearer, faster, and more maintainable SQL. This article explains what they are, how they differ, and when to use each. What … Read more
When choosing a database for an application, one of the fundamental decisions is whether to use an SQL (relational) or NoSQL (non-relational) database. Both have their strengths and weaknesses, making them suitable for different use cases. This article explores the key differences between SQL and NoSQL databases, their advantages, and when to use each. What … Read more
Databases are classified into structured and unstructured databases based on how they store and manage data. Depending on the nature of the data and the application’s requirements, both types serve different purposes and are used in different scenarios. Structured Databases Structured databases, also known as relational databases (RDBMS), store data in a highly organized manner … Read more
Query Collections Duplicate value Delete Duplicate Records While Keeping One Efficiently remove duplicates but keep one copy. Way 1 Recommended way cte + window It’s a more modern SQL approach, clearer in intent when dealing with duplicates, and easier to adapt for more complex rules. Read Further Way 2: subquery Nth Largest Value Replace query … Read more
When Sun Microsystems acquired MySQL in 2008, the future looked bright for this widely-used open-source database. However, things took a sharp turn when Oracle Corporation, a major player in proprietary software, acquired Sun the following year. Concerns quickly grew within the open-source community, and many feared Oracle might alter MySQL’s development course, potentially shifting it … Read more
SQL wildcards (% and _) can be powerful for pattern matching, but they can also have performance implications, especially on large datasets. Here’s a breakdown of their usage and impact on performance: Leading Wildcards (%pattern) Performance Impact: Using a leading % disables index usage, as the database must perform a full scan to find matches. … Read more
Database engines (or storage engines) are the underlying systems that manage how data is stored, retrieved, and manipulated within a database. Each engine has its own unique set of features, optimizations, and limitations. MySQL, one of the most popular open-source SQL databases, supports multiple storage engines, the most widely used being MyISAM and InnoDB. Other … Read more
SQL query optimization is essential to ensure your database applications run smoothly and efficiently, especially as data grows. Optimized SQL queries can significantly improve response times, reduce server load, and enhance the user experience. This guide provides a step-by-step approach to optimizing SQL queries, covering best practices, tips, and strategies to make your queries faster … Read more
The EXPLAIN statement in SQL is a powerful diagnostic tool that helps you understand and optimize your database queries, especially in relational databases like MySQL. By using EXPLAIN, you can see how your queries interact with your tables, which indexes are used, and the estimated costs of each operation. Understanding the output of EXPLAIN is … Read more