1. The Relational Model & Relational Algebra
Why flat files fail, how the relational model solved data independence, and the algebra behind every SQL query.
Relational algebra, query optimization, storage engines, and database internals.
Why flat files fail, how the relational model solved data independence, and the algebra behind every SQL query.
Aggregates, GROUP BY, string ops, nested queries, lateral joins, CTEs, and window functions — the SQL features that go beyond basic SELECT.
How a disk-oriented DBMS organizes files, pages, and tuples on disk — from the storage hierarchy down to slotted pages and word-aligned tuple layouts.
How a DBMS manages memory with a buffer pool: replacement policies, why mmap fails, and optimizations like prefetching and scan sharing.