Which database model is primarily used for applications needing simple access without complex querying?

The key-value pair database model is well-suited for applications that require simple access patterns without the need for complex querying. In this model, data is organized as a collection of key-value pairs, where each key is unique and corresponds directly to its value. This structure allows for quick retrieval of data since accessing a value is as simple as knowing its key.

This model is particularly beneficial for scenarios where the application primarily needs to store and retrieve data quickly without the overhead associated with complex queries or relationships typical of other database models. Such simplicity in design makes key-value databases efficient for caching and session management, among other use cases, where speed of access is critical and the data structure is straightforward.

In contrast, relational databases rely on complex relationships and structured queries, while document-oriented databases handle semi-structured data more flexibly, and time-series databases are specialized for managing and analyzing time-stamped data. The key-value database model's straightforward access mechanism makes it an optimal choice for applications emphasizing speed and simplicity.