SOLR/Lucene index return unique results

I have an index th开发者_JAVA百科at has multiple entries for the exact same item, i specified a : <uniqueKey>citation</uniqueKey> based on citation, a field that i can use to determine it is unique in the index.

I was wondering if there is some way to adjust the query so that it will only return unique results based on that field.

or rather to delete all duplicates, but the problem with that which ive run into is that I am not storing the text, and the only other unique way to identify documents is based on two fields combined. I am hoping there is a way to do this without needing a new index.

thanks

I think you need Field Collapsing. You may be able to pull this off without reindexing, but I believe the queries take a relatively long time.