Model → query → plan → transaction
Data
From reading a first SQL query to execution plans, concurrent transactions, locks, and deliberate ORM boundaries.
- Chapters
- 5
- Learning tracks
- 2
- PRODUCTION CASES
- 5
What this sphere covers
SQL foundations
queries · schema · ACID · constraints
- CHAPTER 14SQL from zero: reading and changing rowsStatement → clauses → result rows
Learn to read SELECT, WHERE, INSERT, UPDATE, DELETE, NULL, parameters, sorting, and aggregation before advanced database topics.
- CHAPTER 15SQL foundations, ACID, and constraintsInvariant → transaction → durable state
Use real PostgreSQL constraints, parameterized SQL, and a rollback to see where data integrity actually lives.
PostgreSQL in practice
EXPLAIN · isolation · JOIN · views
- CHAPTER 16PostgreSQL indexes and EXPLAINStatistics → plan → measured trade-off
Build B-tree, Hash, BRIN, and GIN indexes, then compare a real EXPLAIN ANALYZE plan before and after indexing.
- CHAPTER 17Transaction isolation and lockingSnapshots → contention → conflict handling
Open two real PostgreSQL sessions and compare Read Committed, Repeatable Read, SELECT FOR UPDATE, and optimistic versioning.
- CHAPTER 18JOINs, Materialized Views, and ORM boundariesData shape → round trips → freshness
Inspect a real JOIN plan, reproduce N+1, and watch a Materialized View remain stale until REFRESH.