Dirty Read
A transaction anomaly in which one transaction reads changes made by another transaction before those changes are committed.
Database Context
A dirty read occurs when one transaction observes another transaction's changes before they commit. If the writer later rolls back, the reader has acted on a database state that never became durable. Read Committed and stronger isolation levels are designed to prevent this anomaly.
Isolation Boundary
A dirty read is different from a stale read. Stale data may come from a committed but outdated replica or cache; dirty data originates from an uncommitted transaction.
Related Database Concepts
- Transaction Isolation
- Read Committed
- Rollback
- Stale Read