Two-Phase Locking (2PL) and Serialized Schedules

This generated surface maps a learner-facing curriculum unit to its canonical source routes.

Curriculum surface

• Open learner-facing unit
• Curriculum path: content/curriculum/architecture/semester-06-databases-distributed/module-04-transactions-consistency/concepts/cluster-03-implementing-isolation/07-two-phase-locking-2pl-and-serialized-schedules-primary.md
• App: architecture
• Semester: semester-06-databases-distributed
• Module: module-04-transactions-consistency
• Unit kind: concept
• Curation level: module_curated

Learning objectives

• Explain Two-Phase Locking (2PL) and Serialized Schedules using the language of guarantees, anomalies, and implementation costs rather than vague “strong vs weak” intuition.
• Use Two-Phase Locking (2PL) and Serialized Schedules to reason about what a database actually promises under concurrency and failure.
• Use database-internals, database-system-concepts, ddia to connect the learner-facing model to isolation, recovery, distributed coordination, and real failure modes.

Prerequisites

• Comfort with relational data modeling and the basic mechanics of storage engines and replication.

Source books

• database-internals
• database-system-concepts
• ddia

Source routes

Database Internals

• /books/database-internals/chapter-02-b-tree-basics via Database Internals: Lock-based concurrency control (part 1), Database Internals: Lock-based concurrency control (part 2)

Database System Concepts

• /books/database-system-concepts via Database System Concepts: Deadlock handling (part 1), Database System Concepts: Lock-based protocols (part 1)

Ddia

• /books/ddia/chapter-02-data-models-and-query-languages via DDIA: Two-phase locking (part 2)
• /books/ddia/chapter-07-transactions via DDIA: Two-phase locking (part 1)

Supporting curriculum routes

No supporting curriculum routes linked yet.

External enrichment

• PostgreSQL Documentation: Transaction Isolation (official_docs_companion) - Anchors anomaly and isolation discussions in a concrete implementation instead of abstract labels alone.
• CockroachDB: Transaction Layer Architecture (optional_deep_dive) - Useful when the learner wants to see how transactional guarantees change under a distributed SQL architecture.

AI companion modes

• Explain simply
• Socratic tutor
• Challenge my understanding
• Diagnose my confusion
• Connect forward / backward

Source-of-truth note

This teaching unit is learner-facing guidance assembled from multiple canonical book routes. Use the listed source books as the primary conceptual spine for Two-Phase Locking (2PL) and Serialized Schedules, and treat outside material as supporting enrichment only.