DiskANN construction is much much slower than HNSW, and the support around updates has been discussed in literature but has not been open sourced yet (They call

DiskANN construction is much much slower than HNSW, and the support around updates has been discussed in literature but has not been open sourced yet (They call this FreshDiskANN in the paper - DiskANN is from microsoft research btw). HNSW-IF is an excellent extension to HNSW (that the vespa team has made easy to implement) that takes advantage of the speed/recall of HNSW in combination with the disk scalability of inverted indices - it is a hybrid approach.