added validation

mapping/field.go

@@ -78,7 +78,7 @@ type FieldMapping struct {
 	// See: index.DefaultSimilarityMetric & index.SupportedSimilarityMetrics
 	Similarity string `json:"similarity,omitempty"`
 
-	VectorIndexType string `json:"vectorIndexType,omitempty"`
+	VectorIndexType string `json:"vector_index_type,omitempty"`
 }
 
 // NewTextFieldMapping returns a default field mapping for text
@@ -468,7 +468,11 @@ func (fm *FieldMapping) UnmarshalJSON(data []byte) error {
 			if err != nil {
 				return err
 			}
-		// add condition here too!
+		case "vector_index_type":
+			err := json.Unmarshal(v, &fm.VectorIndexType)
+			if err != nil {
+				return err
+			}
 		default:
 			invalidKeys = append(invalidKeys, k)
 		}

mapping/mapping_vectors.go

@@ -162,6 +162,10 @@ func validateVectorFieldAlias(field *FieldMapping, parentName string,
 		field.Similarity = index.DefaultSimilarityMetric
 	}
 
+	if field.VectorIndexType == "" {
+		field.VectorIndexType = index.DefaultIndexType
+	}
+
 	// following fields are not applicable for vector
 	// thus, we set them to default values
 	field.IncludeInAll = false
@@ -202,6 +206,12 @@ func validateVectorFieldAlias(field *FieldMapping, parentName string,
 			reflect.ValueOf(index.SupportedSimilarityMetrics).MapKeys())
 	}
 
+	if _, ok := index.SupportedIndexTunables[field.VectorIndexType]; !ok {
+		return fmt.Errorf("field: '%s', invalid index optimisation "+
+			"tunable: '%s', valid values are: %+v", field.Name, field.VectorIndexType,
+			reflect.ValueOf(index.SupportedIndexTunables).MapKeys())
+	}
+
 	if fieldAliasCtx != nil { // writing to a nil map is unsafe
 		fieldAliasCtx[field.Name] = field
 	}