No. Siren Platform supports for External Data sources such as typically JDBC connections and generic REST sources.

Siren Platform can query these sources on the fly at user navigation to create special filters or special “external query” aggregators (e.g. to use in visualizations).

Generally speaking, you should load the data where you intend to perform search and complex analytics. But you do not need to materialize or import auxiliary data that is only used for visualizations or to create filters.