Which statement best describes a relational database (SQL)?

Which statement best describes a relational database (SQL)?

• A. Data is organized into tables with fixed schemas and ACID guarantees.
• B. Data is stored as flexible JSON-like documents with embedded related data.
• C. Data is organized into key-value pairs only with no schema.
• D. Graph labeling defines data types in a graph database.

Answer: (A)

Relational databases organize data into tables with predefined columns and data types, creating a fixed schema that enforces data integrity. They use SQL for structured querying and provide ACID guarantees—Atomicity, Consistency, Isolation, and Durability—that ensure reliable, correct transactions even with concurrent access or after failures. Relationships are modeled with keys and can be combined through JOIN operations, which helps maintain normalized data without duplicating information. This contrasts with document stores that use flexible JSON-like documents, key-value stores with no schema, and graph databases that focus on nodes, edges, and labeled types for traversing relationships.

Relational databases organize data into tables with predefined columns and data types, creating a fixed schema that enforces data integrity. They use SQL for structured querying and provide ACID guarantees—Atomicity, Consistency, Isolation, and Durability—that ensure reliable, correct transactions even with concurrent access or after failures. Relationships are modeled with keys and can be combined through JOIN operations, which helps maintain normalized data without duplicating information. This contrasts with document stores that use flexible JSON-like documents, key-value stores with no schema, and graph databases that focus on nodes, edges, and labeled types for traversing relationships.