Definition: The state in which all instances of data across different databases or within a distributed system are identical at any given time. Data consistency ensures that data is accurate and up-to-date everywhere.
Key Features:
Integrity: Data remains unchanged unless a change is required.
Reliability: Data always reflects the current and correct state.
Synchronicity: In distributed systems, data updates are carried out simultaneously across all parts of the system.
Common Challenges:
Network Failures: Can lead to inconsistencies in distributed databases.
Concurrent Access: Multiple users or processes accessing and modifying data at the same time can cause inconsistencies.
System Failures: Unforeseen errors can compromise data integrity.
Applications: Database management systems, distributed systems, cloud computing, and any application where data is stored and retrieved.