Which interaction composition primitive involves executing multiple queries in response to a single request?

Aggregation is the interaction composition primitive that involves executing multiple queries in response to a single request. This concept focuses on gathering data from various sources and presenting it as a unified output, effectively allowing users to perform a single operation that aggregates results from multiple queries or endpoints.

In scenarios where you need to compile data from diverse services or databases, aggregation enables the system to efficiently handle these multiple queries simultaneously and return a consolidated result to the requester. This makes it ideal for use cases where data from different systems is necessary for a comprehensive response.

Other options like orchestration refer more to the coordination of multiple services or workflows but do not specifically deal with executing multiple queries simultaneously from a single request. Choreography focuses on the interactions between services without a central controlling service, while batching involves grouping multiple requests into a single operation for performance reasons rather than for the purpose of executing multiple queries in one go. Therefore, aggregation is the most accurate primitive for this scenario.