Transactions and Concurrency

Deadlock Handling

0:00

0% complete

LearnStep 1 of 2

Deadlocks in DBMS

Learning Objectives

•Understand deadlocks
•Learn prevention and recovery

Lesson Outline

LearnStep 1/2

Deadlocks in DBMS

Deadlocks in Database Systems

Deadlock Example

Handling Strategies

1. Detection and Recovery

2. Prevention (Timestamps)

Wait-Die: Older waits, younger aborts

Wound-Wait: Older preempts, younger waits

3. Timeout

sql

Victim Selection Criteria

Amount of work done (rollback cost)
Time remaining to complete
Number of locks held
Priority