📄️ ACID
Understand the four guarantees — Atomicity, Consistency, Isolation, and Durability — that database transactions provide to ensure data integrity.
📄️ Aggregation & Filtering
Master SQL aggregation with GROUP BY, aggregate functions, WHERE vs HAVING, and DISTINCT vs GROUP BY — with diagrams, examples, and interview questions.
📄️ Joins
Master SQL JOIN operations — inner join, left join, right join, full outer join, cross join, and self join — with diagrams, examples, and performance tips.
📄️ Indexing
Watch a side-by-side comparison of full table scan vs B-tree index traversal. See how indexes dramatically reduce the number of operations needed to find data.
📄️ Materialized Views
Watch how materialized views precompute expensive queries into stored snapshots. See the build, query, and refresh lifecycle in action.
📄️ Replication
Watch how write operations propagate across primary and replica nodes under different replication strategies — synchronous, asynchronous, and multi-leader.
📄️ Sharding
Watch how write operations get routed to different shards under hash-based, range-based, and directory-based sharding strategies.
📄️ Caching
How database caching works — cache hits and misses, read/write strategies, invalidation, eviction policies, and common pitfalls.
📄️ Locking
Understand pessimistic and optimistic locking strategies — when to use each, how they work, and their trade-offs for data consistency in concurrent environments.
📄️ Primary & Foreign Keys
Understand primary keys and foreign keys — how they work, how they differ, and how they enforce data integrity and relationships in relational databases.
📄️ Stored Procedures
Master SQL stored procedures — creation, parameters, control flow, error handling, and best practices. Compare with functions, understand performance implications, and learn when to use them.
📄️ UNION
Master SQL set operations — UNION, UNION ALL, INTERSECT, and EXCEPT — with clear examples, performance tips, and interview questions.