This chapter covers, for junior engineers and focused narrowly on design-time decisions, how an index speeds up search (the intuition behind B-Trees), which columns to index (WHERE / JOIN / ORDER BY), composite-index column order, partial indexes, how to read EXPLAIN, the harm of over-indexing, and compatibility with UUID primary keys.
This chapter explains, for junior engineers, the role of a DBMS (SQL parsing, transaction management, permissions, optimization), the four categories of SQL (DDL/DML/DCL/TCL), and the characteristics and trade-offs of major RDBMS products (PostgreSQL / MySQL / SQLite / Oracle / SQL Server).
This chapter organizes the operational tasks RDS handles as a managed service versus the design decisions Tasuku owns, covering instance class, storage, and Multi-AZ selection, master password integration with Secrets Manager, and completing the security group chain. It closes with a connectivity check using run-task and psql.