*: tiny update

pkg/ddl/generated_column.go

@@ -303,8 +303,8 @@ func (c *illegalFunctionChecker) Enter(inNode ast.Node) (outNode ast.Node, skipC
 			return inNode, true
 		}
 		if c.genType == typeVectorIndex {
-			_, ok := ast.IsVectorIndexDistanceMetricSupported[node.FnName.L]
-			if ok {
+			_, isFunc4Vec := variable.DistanceMetric4VectorIndex[node.FnName.L]
+			if isFunc4Vec {
 				c.hasFunc4VectorIdx = true
 				if len(node.Args) != 1 {
 					c.otherErr = expression.ErrIncorrectParameterCount.GenWithStackByArgs(node.FnName)

pkg/ddl/index.go

@@ -403,7 +403,7 @@ func buildVectorInfoWithCheck(indexPartSpecifications []*ast.IndexPartSpecificat
 		return nil, "", dbterror.ErrUnsupportedAddVectorIndex.FastGenByArgs(fmt.Sprintf("unsupported function: %v", idxPart.Expr))
 	}
 
-	_, ok = ast.IsVectorIndexDistanceMetricSupported[f.FnName.L]
+	distanceMetric, ok := variable.DistanceMetric4VectorIndex[f.FnName.L]
 	if !ok {
 		return nil, "", dbterror.ErrUnsupportedAddVectorIndex.FastGenByArgs("unsupported function")
 	}
@@ -416,7 +416,6 @@ func buildVectorInfoWithCheck(indexPartSpecifications []*ast.IndexPartSpecificat
 		return nil, "", infoschema.ErrColumnNotExists.GenWithStackByArgs(colExpr.Name.Name.String())
 	}
 
-	distanceMetric := model.DistanceMetric(f.FnName.L)
 	// check duplicated function on the same column
 	for _, idx := range tblInfo.Indices {
 		if idx.VectorInfo == nil {

pkg/executor/show.go

@@ -1229,7 +1229,8 @@ func constructResultOfShowCreateTable(ctx sessionctx.Context, dbName *model.CISt
 			cols = append(cols, colInfo)
 		}
 		if idxInfo.VectorInfo != nil {
-			fmt.Fprintf(buf, "((%s(%s)))", strings.ToUpper(string(idxInfo.VectorInfo.DistanceMetric)), strings.Join(cols, ","))
+			funcName := variable.Function4VectorIndex[idxInfo.VectorInfo.DistanceMetric]
+			fmt.Fprintf(buf, "((%s(%s)))", strings.ToUpper(funcName), strings.Join(cols, ","))
 		} else {
 			fmt.Fprintf(buf, "(%s)", strings.Join(cols, ","))
 		}

pkg/parser/model/model.go

@@ -1449,10 +1449,11 @@ type DistanceMetric string
 
 // Note: tipb.VectorDistanceMetric's enum names must be aligned with these constant values.
 const (
-	// DistanceMetricL2 is L2 distance.
-	DistanceMetricL2 DistanceMetric = "vec_l2_distance"
+	DistanceMetricL2 DistanceMetric = "L2"
 	// DistanceMetricCosine is cosine distance.
-	DistanceMetricCosine DistanceMetric = "vec_cosine_distance"
+	DistanceMetricCosine DistanceMetric = "COSINE"
+	// DistanceMetricInnerProduct is inner product.
+	DistanceMetricInnerProduct DistanceMetric = "INNER_PRODUCT"
 )
 
 // VectorIndexInfo is the information of vector index of a column.

pkg/sessionctx/variable/varsutil.go

@@ -29,6 +29,7 @@ import (
 	"github.com/pingcap/errors"
 	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/parser/charset"
+	"github.com/pingcap/tidb/pkg/parser/model"
 	"github.com/pingcap/tidb/pkg/parser/mysql"
 	"github.com/pingcap/tidb/pkg/types"
 	"github.com/pingcap/tidb/pkg/util/collate"
@@ -632,3 +633,15 @@ func parseSchemaCacheSize(s *SessionVars, normalizedValue string, originalValue
 
 	return 0, "", ErrTruncatedWrongValue.GenWithStackByArgs(TiDBSchemaCacheSize, originalValue)
 }
+
+// DistanceMetric4VectorIndex stores distance metrics for the vector index.
+var DistanceMetric4VectorIndex = map[string]model.DistanceMetric{
+	ast.VecCosineDistance: model.DistanceMetricCosine,
+	ast.VecL2Distance:     model.DistanceMetricL2,
+}
+
+// Function4VectorIndex stores functions for the vector index.
+var Function4VectorIndex = map[model.DistanceMetric]string{
+	model.DistanceMetricCosine: ast.VecCosineDistance,
+	model.DistanceMetricL2:     ast.VecL2Distance,
+}