Commit Protocols Flashcards
1
Q
What are the ACID properties?
A
Atomicity, Consistency, Independence, Durability
2
Q
What is the point of commit protocols in transaction systems?
A
Ensure all nodes commit or abort a transaction as a unified decision
3
Q
When is a transaction in danger of a dealock?
A
When a transactions response to a conflict is to wait for a lock.
4
Q
Name a way to avoid deadlocks.
A
Extinction
5
Q
Locking and Extinction ensures what ACID properties?
A
C and I
6
Q
What are the phases of 2-phase commit protocool?
A
- Coordinator collects yes/no from all servers
- Coordinator enforces the decision (commit/abort)
7
Q
Why is 2PC blocking?
A
If coordinator crashes in phase 2, servers in “wait” state will be waiting for recovery
8
Q
How does 3PC differ and improve over 2PC?
A
Adds a pre-commit state to reduce blocking.
