title: Exporting index from Solr to a file, with fields illegal for FieldCache
body: <p>I'm trying to export Solr index to a JSON file. However, among the 2 fields I care about, one of them (field <code>A</code>) is <code>multivalued</code>, another (field <code>B</code>) <code>neither indexed nor has doc values</code> (this field is probably missing schema). Both cause error that says <code>can not use FieldCache on a field which is ...</code></p>
  
  <p>The schemas of these fields is on remote server, and shouldn't be changed. Is it possible then to export the index with these fields anyway? Thank you!</p>
  
  <p>p.s. If possible I would also like to <code>fl</code> on these 2 fields since they are all I need.</p>