When the pull mapper is in use GSS requires more information about the entities being used in the search services. For each unique entity listed in the child searchServiceField records belonging to each SearchService using the Pull Mapper, a GSSEntity record must be added (however if multiple fields belong to the same entity, you don't need to repeat the information).
The Search Service Identifier; a string used to uniquely identify a Search Service. This is a foreign key of the SearchService table.
This is the full classname of the struct that is the parameter to your modelled searchByLastwritten method described here: Modelling the table scan.
This is the full classname of the parameter struct to your entity's read method.
This is the full classname of the generated factory class for your entity.