What is data consistency in SQL and NoSQL databases?

What is data consistency in SQL and NoSQL databases?

Data consistency refers to the accuracy and reliability of data across databases. In SQL, it often follows ACID properties, ensuring transactions are processed reliably. In NoSQL, consistency can vary, often prioritizing availability and partition tolerance over strict consistency.

Can you explain the ACID properties in SQL?

Sure! ACID stands for Atomicity, Consistency, Isolation, and Durability. These properties ensure that database transactions are processed reliably. Atomicity guarantees that all operations in a transaction are completed successfully or none at all. Consistency ensures that a transaction brings the database from one valid state to another. Isolation ensures that transactions do not interfere with each other, and Durability guarantees that once a transaction is committed, it remains so even in the event of a system failure.

How does NoSQL handle data consistency differently?

NoSQL databases often use eventual consistency rather than strict consistency. This means that while data may not be immediately consistent across all nodes, it will eventually become consistent. This approach allows for greater scalability and availability, which is crucial for distributed systems.

What are some examples of NoSQL databases?

Some popular NoSQL databases include MongoDB, Cassandra, Redis, and Couchbase. Each has its own strengths and is suited for different types of applications.