CompTIA DataSys+ (DS0-001)Database Management and MaintenanceHard
A database administrator is reviewing the database's error logs and notices a recurring warning about 'deadlocks'. Upon further investigation, they find that these deadlocks frequently occur between two specific transactions that update different rows in the same table. Which database property, if enforced, could help prevent these specific deadlocks?
- AAtomicity
- BIsolation
- CDurability
- DConsistency
Show answer & explanationAnswer & explanation
Correct answer: B. Isolation
Deadlocks arise from concurrent transactions attempting to acquire locks on resources held by each other. Isolation, one of the ACID properties, dictates how transactions interact with each other and can be configured to prevent or resolve such conflicts by controlling locking behavior and visibility of uncommitted changes.
Why the other options are wrong
- A. Atomicity ensures all or nothing, not deadlock prevention between concurrent transactions.
- C. Durability ensures committed data persists, not related to concurrent access conflicts like deadlocks.
- D. Consistency ensures data integrity after a transaction, not direct deadlock prevention.
Isolation (ACID)
The 'I' in ACID, ensuring that concurrent transactions execute independently without interfering with each other's operations.
- Achieved through locking mechanisms.
- Higher isolation levels reduce concurrency but increase data consistency.
- Lower isolation levels increase concurrency but may lead to phenomena like dirty reads.
Memory trick: ACID: Atomic, Consistent, Isolated, Durable. Isolation solves lock fights.