fix: incorrect dim set when creating BM25 doc sparse array (#37717)

issue: #35853

Signed-off-by: Buqian Zheng <[email protected]>

internal/storage/stats.go

@@ -458,9 +458,9 @@ func (m *BM25Stats) Deserialize(bs []byte) error {
 }
 
 func (m *BM25Stats) BuildIDF(tf []byte) (idf []byte) {
-	dim := typeutil.SparseFloatRowElementCount(tf)
+	numElements := typeutil.SparseFloatRowElementCount(tf)
 	idf = make([]byte, len(tf))
-	for idx := 0; idx < dim; idx++ {
+	for idx := 0; idx < numElements; idx++ {
 		key := typeutil.SparseFloatRowIndexAt(tf, idx)
 		value := typeutil.SparseFloatRowValueAt(tf, idx)
 		nq := m.rowsWithToken[key]

internal/util/function/bm25_function.go

@@ -107,7 +107,7 @@ func (v *BM25FunctionRunner) run(data []string, dst []map[uint32]float32) error
 
 func (v *BM25FunctionRunner) BatchRun(inputs ...any) ([]any, error) {
 	if len(inputs) > 1 {
-		return nil, fmt.Errorf("BM25 function receieve more than one input")
+		return nil, fmt.Errorf("BM25 function received more than one input column")
 	}
 
 	text, ok := inputs[0].([]string)
@@ -158,16 +158,18 @@ func (v *BM25FunctionRunner) GetOutputFields() []*schemapb.FieldSchema {
 }
 
 func buildSparseFloatArray(mapdata []map[uint32]float32) *schemapb.SparseFloatArray {
-	dim := 0
+	dim := int64(0)
 	bytes := lo.Map(mapdata, func(sparseMap map[uint32]float32, _ int) []byte {
-		if len(sparseMap) > dim {
-			dim = len(sparseMap)
+		row := typeutil.CreateAndSortSparseFloatRow(sparseMap)
+		rowDim := typeutil.SparseFloatRowDim(row)
+		if rowDim > dim {
+			dim = rowDim
 		}
-		return typeutil.CreateAndSortSparseFloatRow(sparseMap)
+		return row
 	})
 
 	return &schemapb.SparseFloatArray{
 		Contents: bytes,
-		Dim:      int64(dim),
+		Dim:      dim,
 	}
 }