What data store type is used for hosted feature layer data in a portal?

The correct answer is the relational data store, as it is specifically designed for storing hosted feature layers within the ArcGIS environment. Hosted feature layers represent collections of geographical features and their associated attributes, which are typically managed using a relational database framework. This allows for robust data management capabilities, including structured querying and relationships between different data tables.

In this context, the relational data store provides essential support for operations like editing, querying, and analyzing feature layers in a web environment. It facilitates the efficient handling of spatial data alongside its non-spatial attributes, making it ideal for the types of interactions and workflows expected in a portal setup.

While other data store types mentioned serve different purposes, they do not relate directly to the use of hosted feature layers. For instance, tile cache data stores are intended for pre-rendering and serving map tiles, spatiotemporal big data stores cater to handling large datasets with a focus on time-based analysis, and continuous data stores are more associated with real-time data ingestion and processing. Thus, the relational data store is the most suitable and commonly utilized type for managing hosted feature layer data in a portal.