I'm working with solr5.2 and I'm using termVectors with solrj (but an answer not using solrj would be nice as well).
From a first query, I obtain termVectors, and I'd like to query again my index with some of the terms from these termVectors.
However the terms from termVectors are obviously already stemmed, and I'd like to go directly to the corresponding entry in the index, without going through the query analysis step (otherwise, my stem will be stemmed again, which can lead to a different entry).
A workaround would be to stem all terms at indexing time, and to index them in a separate String field, but I'd like to avoid this ugly solution. Is there a better way?
You can define separate analysis chains for query and indexing (I read your caveat as having to do it outside of Solr, as you're talking about String fields):
<analyzer type="index">
So you could have one field that does not perform stemming on query, just on indexing. That might not be suitable for your primary field, so add a second one and use copyField to index into that field as well.