Then, we needed to tell the CSV handler which fields can have multiple values and how to break them apart. That's what
f.addr_to.separator do, where
addr_to is the name of the field as defined in the
schema.xml file. The
f.<fieldname>.<option> approach is a standard Solr one for per-field settings.
How to do that? add it schema.xml? could not find such settings in the example files: https://github.com/arafalov/solr-indexing-book/tree/master/published/multivalued