Relational foundations, SQL, transactions, indexing, and the scaling strategies behind every data layer decision.
Relational foundations, SQL, transactions, indexing, and the scaling strategies behind every data layer decision.
Database Basics
Tables, relationships, constraints, and the SQL vs NoSQL decision — the relational model from first principles.
Normalization
1NF, 2NF, 3NF, and when to break the rules — designing schemas that eliminate redundancy without sacrificing performance.
SQL Joins
INNER, LEFT, RIGHT, FULL OUTER, and self joins — how relational algebra maps to SQL and when to use each join type.
Transactions & Isolation Levels
ACID guarantees, concurrency anomalies, and the four isolation levels — what your database actually promises under concurrent load.
Indexing
B-Tree, hash, and composite indexes — how database indexes work, when to use them, and when to avoid them.
Geospatial Indexing
Geohashing, Quadtrees, R-Trees, and the spatial query techniques behind location search, ride-sharing, and proximity features.
Replication & Sharding
Read replicas, horizontal partitioning strategies, and consistent hashing — how databases scale reads and writes beyond a single node.