Just curious if anyone has had success combining multiple rerankers in
Solr. At least one of which uses the LTR query.
1. I can issue an LTR query and score the entire corpus with an LTR model
q={!ltr ...}
2. I can naturally use LTR in rq itself rq={!ltr...} and do one rerank
pass, entirely in LTR
3. Multiple rq parameters do not seem supported (one is chosen at random)
4. Using an {!rerank, wrapping ltr and another query in a larger function
query does not work - wrapping LTR in "query()" always returns 1.
Note on 4 - the explain actually will show a different score than if you
add "score" to fl. Which will lead you to think this works. When in fact,
adding / removing the LTR from such a function query shows its having no
effect (and the explain scores don't match what's returned in fl=score).
This is in Solr 9.3.1.
Has anyone had much luck being able to rerank with multiple stages or
combine multiple rerankers in Solr?
Thanks!
-Doug
