How do SQL and NoSQL databases differ, and when would you choose each?

How do SQL and NoSQL databases differ, and when would you choose each?

• A. SQL is relational with structured schemas; NoSQL handles unstructured/scalable data; use SQL for structured data, NoSQL for big or flexible data.
• B. NoSQL is relational with structured schemas; SQL handles unstructured data.
• C. SQL stores only text; NoSQL stores numbers.
• D. SQL is unscalable; NoSQL is fixed schema.

Answer: (A)

SQL databases are relational and use structured schemas with tables and defined relationships, while NoSQL databases are designed for unstructured or semi-structured data and often scale horizontally to handle large workloads. You’d choose SQL when your data is highly structured, relationships matter, and you need reliable transactions and the ability to perform complex queries. NoSQL is a better fit when you’re dealing with diverse or rapidly changing data, very large data volumes, or the need for flexible schemas and high-speed, scalable storage—where you might trade some strict consistency for performance and scalability. The other statements mix up these ideas: NoSQL isn’t relational with fixed schemas, SQL isn’t limited to text and can store many data types, and SQL databases can be scalable with proper design while NoSQL isn’t inherently fixed in schema.

SQL databases are relational and use structured schemas with tables and defined relationships, while NoSQL databases are designed for unstructured or semi-structured data and often scale horizontally to handle large workloads. You’d choose SQL when your data is highly structured, relationships matter, and you need reliable transactions and the ability to perform complex queries. NoSQL is a better fit when you’re dealing with diverse or rapidly changing data, very large data volumes, or the need for flexible schemas and high-speed, scalable storage—where you might trade some strict consistency for performance and scalability.

The other statements mix up these ideas: NoSQL isn’t relational with fixed schemas, SQL isn’t limited to text and can store many data types, and SQL databases can be scalable with proper design while NoSQL isn’t inherently fixed in schema.