[SOLR-16246] Implement pre-filtering functionallity for KnnQParser

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Done
• Fix Version/s: 9.1
• Assignee: Alessandro Benedetti
• Reporter: Elia Porciani
• Created: 09/Jun/22 16:08
• Updated: 10/Jan/23 20:45
• Resolved: 26/Jul/22 16:47

Description

At the current state of development, with KnnQParser it is possible to specify filter queries and the result is the intersection between:

• top-K document founds by the KNN search
• Results of the filter query
  As a consequence, if the filter query filters out some documents in the top-K results, we will have less than K results in the result set.

The proposal is to leverage the recent Apache Lucene development LUCENE-10382 to change the behavior of the filter queries in the KnnQParser in such a way:

• The filter query works as pre-filtering
• KNN Search retrieves the top-K results among the documents that are not filtered out.

Issue Links

• links to: GitHub Pull Request #904