Distributed Databases Questions Medium
Data consistency in a distributed database system refers to the property that ensures all copies of data across multiple nodes or sites in the system are synchronized and up-to-date. It guarantees that any read operation on the database will always return the most recent and accurate data.
To achieve data consistency, distributed database systems employ various techniques such as replication, synchronization protocols, and distributed transactions. Replication involves maintaining multiple copies of data across different nodes, ensuring that any updates made to one copy are propagated to all other copies. Synchronization protocols, such as two-phase commit, are used to coordinate and ensure that all nodes agree on the outcome of a transaction before committing it. Distributed transactions allow multiple operations across different nodes to be treated as a single atomic unit, ensuring that either all operations are successfully completed or none of them are.
Data consistency is crucial in distributed databases as it ensures that users accessing the system see a consistent view of the data, regardless of which node they are connected to. It prevents data anomalies, such as conflicting or outdated information, and maintains the integrity and reliability of the database system.