Retrieve Stored Parameters Stage
This stage was renamed to Retrieve Stored Parameters in Fusion 3.0. It was called the Stored Parameters stage in prior Fusion versions.
The Retrieve Stored Parameters stage is used to add parameters to the downstream Solr query stage in the pipeline. The primary use case for this query stage is in eCommerce applications to organize and enhance search query results, where the parameters added to the Solr query are used for faceting. This stage is used in query pipelines for applications where the documents in the collection are to be classified according to a known category hierarchy that is stored in Fusion as an auxiliary "stored parameters" collection.
The information in a taxonomy is meta-information about the categories used to classify a set of things. For an eCommerce site, the set of things are items in the product catalog, which are stored in a Fusion collection, referred to as the primary collection. The taxonomy itself is specified as a set of categories which are stored in an auxiliary collection and naming conventions relate the primary and auxiliary collections so that for a primary collection named "COLL", the auxiliary taxonomy is stored in a collection named "COLL_stored_parameters".