Columnar Storage and Query Optimization

Every data professional writes SQL queries — but few understand why some queries take seconds and others take minutes on the same data. The answer lies beneath the surface: in how data is stored, how query engines read that data, and how columnar formats like Parquet fundamentally change the game for analytics performance. This course gives you that understanding. You will start from the foundations — how computers store and read data, how SQL operations access data internally, and what distinguishes row-based storage from columnar storage. From there, you will explore modern columnar formats…