Hybrid search

When you want the recall of a vec.KNN semantic match and the precision of an fts.Index.Search lexical match, the fusion sub-package merges two ranked result sets into one via Reciprocal Rank Fusion (Cormack 2009). No SQL, no extension to load — just Go ranking, no SQLite dependency.

import "gosqlite.org/fusion"

vecHits, _ := tbl.KNNSlice(ctx, queryVec, 50)
ftsHits, _ := idx.SearchSlice(ctx, fts.Term("brown fox"), fts.WithLimit(50))

vecKeys := make([]int64, len(vecHits))
for i, h := range vecHits { vecKeys[i] = h.Rowid }
ftsKeys := make([]int64, len(ftsHits))
for i, h := range ftsHits { ftsKeys[i] = h.Key }

top, err := fusion.RRF([][]int64{vecKeys, ftsKeys}, fusion.WithLimit(20))
if err != nil { log.Fatal(err) }
for _, r := range top {
  fmt.Println(r.Key, r.Score)
}

fusion.RRF2(a, b) is the two-list convenience form. Runnable: examples/features/search/fusion-hybrid/.

See Vector search and Full-text search for the two halves.