diff --git a/server/handler/util.go b/server/handler/util.go
index 3aac81e949802..9039eed667a21 100644
--- a/server/handler/util.go
+++ b/server/handler/util.go
@@ -17,7 +17,6 @@ package handler
 import (
 	"encoding/json"
 	"net/http"
-	"strings"
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/tidb/parser/terror"
@@ -52,12 +51,14 @@ const (
 
 //revive:enable
 
+// WriteError writes error to response.
 func WriteError(w http.ResponseWriter, err error) {
 	w.WriteHeader(http.StatusBadRequest)
 	_, err = w.Write([]byte(err.Error()))
 	terror.Log(errors.Trace(err))
 }
 
+// WriteData writes data to response.
 func WriteData(w http.ResponseWriter, data interface{}) {
 	js, err := json.MarshalIndent(data, "", " ")
 	if err != nil {
@@ -70,18 +71,3 @@ func WriteData(w http.ResponseWriter, data interface{}) {
 	_, err = w.Write(js)
 	terror.Log(errors.Trace(err))
 }
-
-// ExtractTableAndPartitionName extracts table name and partition name from a string.
-func ExtractTableAndPartitionName(str string) (string, string) {
-	// extract table name and partition name from this "table(partition)":
-	// A sane person would not let the the table name or partition name contain '('.
-	start := strings.IndexByte(str, '(')
-	if start == -1 {
-		return str, ""
-	}
-	end := strings.IndexByte(str, ')')
-	if end == -1 {
-		return str, ""
-	}
-	return str[:start], str[start+1 : end]
-}