# Dbms
All Dbms notes →1 — Transaction Fundamentals
Covers the transaction lifecycle, its states, and the atomicity guarantee that ties them together.
2 — ACID Properties
Covers the four ACID properties — atomicity, consistency, isolation, durability — and what each guarantees.
3 — Concurrency Problems
Covers the concurrency anomalies isolation levels exist to prevent — dirty reads, non-repeatable reads, phantom reads, lost updates, and write skew.
4 — Concurrency Control
Covers lock-based concurrency control — shared and exclusive locks, lock granularity, and intention locks.
5 — Two-Phase Locking
Covers basic, strict, and rigorous two-phase locking and the serializability guarantees each provides.
6 — Timestamp Protocols
Covers timestamp-ordering concurrency control and the Thomas write rule optimization.
7 — Optimistic Concurrency Control
Covers optimistic concurrency control's read/validate/write phases and its rollback behavior on conflict.
8 — Isolation Levels
Covers the standard isolation levels — read uncommitted, read committed, repeatable read, snapshot isolation, and serializable — and which anomalies each permits.