SkillCoded

PostgreSQL

Locks, Blocking, and Deadlock Investigation

Investigate PostgreSQL locks by identifying sessions, granted and waiting requests, blocking chains, transaction scope, and deadlock-safe corrective actions.

Intermediate14 min read
PostgreSQL lessonRelational data foundationsPractice

UNTIMED COACHING

Practice before the pressure

Use feedback to correct the model, not merely memorize an option position.

GUIDED PRACTICE

Practice the lesson questions

Answer normal lesson questions without a timer. Every answer includes an explanation, and incorrect answers can be tried again before continuing.

CONCEPT MODELS

See the lesson as a system

Use these visual guides to connect the key ideas before answering the questions.

Connect the roles in Locks, Blocking, and Deadlock InvestigationKeep database session, lock request, wait evidence, and deadlock outcome as separate roles.
Connect the roles in Locks, Blocking, and Deadlock InvestigationA topic-specific model connects four distinct roles used to reason about locks, blocking, and deadlock investigation.
Session processProcess owns transaction and lock state
Access lockSecurity lock protects a database change
Output evidenceEvidence connects waiter and blocking session
Blocked resultFailure ends one conflicting transaction
Verify Blocking decisionConnect blocking decision with its topic-specific inspection, expected outcome, and protected database boundary.
Verify Blocking decisionA verification model for locks, blocking, and deadlock investigation connects the final data decision to its check, result, and protected boundary.
Selection ruleDecision chooses the narrow corrective action
Starting checkReview selection rule
Expected resultConfirm selection rule
Safety boundaryProtect session process scope