Which type of database system does not use the traditional SQL relational model?

NoSQL databases are designed to provide flexible data models that do not primarily rely on the traditional table-based structure of SQL relational databases. They were developed to handle large volumes of unstructured, semi-structured, or structured data, allowing for scalability and performance that surpasses that of conventional SQL databases in certain scenarios. NoSQL encompasses various types of databases, such as document stores, key-value stores, column-family stores, and graph databases, each suited for different data handling needs.

In contrast, SQL databases are based on the relational model, asserting a fixed schema and employing SQL for data manipulation. Hierarchical databases also follow a specific structured paradigm, organizing data in a tree-like hierarchy, and object-oriented databases utilize objects and classes, maintaining relationships and data in a model inspired by object-oriented programming. All these options rely on established schemas and structure, underscoring the unique flexibility and schema-less nature of NoSQL systems.