Transaction management

Transaction Management

Concept of Transactions

Example Transaction

Properties of Transactions

Transaction Management – to ensure ACID

Concurrency Control

i) Lost Update Problem

ii) Uncommitted Dependency Problem

iii )Inconsistent Analysis Problem

How to handle the 3 problems

a) Serializability

Serializability (continued)

Example of Conflict Serializable Schedules

Example - Non-conflict serializable schedule

b) Concurrency Control Techniques

First Technique - Locking

Example - Incorrect Locking Schedule

c) Two-Phase Locking (2PL)

Preventing Lost Update Problem using 2PL

Preventing Inconsistent Analysis Problem using 2PL

Deadlock

i) Timeouts

ii) Deadlock Prevention

iii) Deadlock Detection and Recovery