with release 9.0 Lucene introduced native ANN support (Lucene Change Log) based on small navigable worlds (~H~SNW). Elasticsearch 8.0 will include a new
_knn_search endpoint (Add new kNN search endpoint by jtibshirani · Pull Request #79013 · elastic/elasticsearch · GitHub) leveraging the new Lucene capability.
Are there any plans on working on integrating the Lucene-native implementation in OpenSearch or OpenSearch kNN?
What’s your assessment of the situation?