Hi Vincenzo, The vector search support in Solr is a work-in-progress with a lot of discussions scattered among some JIRA issues.
Start here: https://issues.apache.org/jira/plugins/servlet/mobile#issue <https://issues.apache.org/jira/plugins/servlet/mobile#issue/SOLR-12890> /SOLR-12890 <https://issues.apache.org/jira/plugins/servlet/mobile#issue/SOLR-12890> Other discussions (some outdated): https://issues.apache.org/jira/plugins/servlet/mobile#issue <https://issues.apache.org/jira/plugins/servlet/mobile#issue/SOLR-13500> /SOLR-13500 <https://issues.apache.org/jira/plugins/servlet/mobile#issue/SOLR-13500> https://issues.apache.org/jira/plugins/servlet/mobile#issue <https://issues.apache.org/jira/plugins/servlet/issue/SOLR-14397>/SOLR-14397 <https://issues.apache.org/jira/plugins/servlet/issue/SOLR-14397> Even though cosine similarity can be used to check similarity among vectors, this solution is not scalable. The state of the art approach for a large number of vectors has been to use Approximate Nearest Neighbors (ANN) algorithms like HNSW graph. So, the related support to ANN algorithms in Lucene has also been discussed: https://issues.apache.org/jira/plugins/servlet/mobile#issue <https://issues.apache.org/jira/plugins/servlet/issue/LUCENE-9004> /LUCENE-9004 <https://issues.apache.org/jira/plugins/servlet/issue/LUCENE-9004> https://issues.apache.org/jira/plugins/servlet/mobile#issue <https://issues.apache.org/jira/plugins/servlet/issue/LUCENE-9136> /LUCENE-9136 <https://issues.apache.org/jira/plugins/servlet/issue/LUCENE-9136> https://issues.apache.org/jira/plugins/servlet/mobile#issue <https://issues.apache.org/jira/plugins/servlet/issue/LUCENE-9322> /LUCENE-9322 <https://issues.apache.org/jira/plugins/servlet/issue/LUCENE-9322> Best, Edward Em sex, 19 de jun de 2020 21:02, Vincenzo D'Amore <v.dam...@gmail.com> escreveu: > Hi all, > > I've started to look at image similarity. For each image in documents I > have a couple of vectors that represent the color and shape similarity. > > As pointer to begin a colleague suggested me to start with this project: > > https://github.com/moshebla/solr-vector-scoring > > but the project seems old and not maintained... On the other hand, looking > at Solr Documentation I see there is support for dot product and cosine > Similarity > > > https://lucene.apache.org/solr/guide/7_5/vector-math.html#dot-product-and-cosine-similarity > > So Solr has the capability to calculate the similarity between two vectors. > But it is not clear how to use this native feature when searching. Am I > missing something? Any help or even suggestion would be appreciated. > > Best regards, > Vincenzo > > > -- > Vincenzo D'Amore >
