diff --git a/session/session.go b/session/session.go
index 1a36431cc355d..e4e513025c458 100644
--- a/session/session.go
+++ b/session/session.go
@@ -393,9 +393,6 @@ func (s *session) FieldList(tableName string) ([]*ast.ResultField, error) {
 	return fields, nil
 }
 
-// mockCommitErrorOnce use to make sure gofail mockCommitError only mock commit error once.
-var mockCommitErrorOnce = true
-
 func (s *session) doCommit(ctx context.Context) error {
 	if !s.txn.Valid() {
 		return nil
@@ -2046,6 +2043,8 @@ func (s *session) recordTransactionCounter(err error) {
 }
 
 type multiQueryNoDelayRecordSet struct {
+	sqlexec.RecordSet
+
 	affectedRows uint64
 	lastMessage  string
 	status       uint16
@@ -2053,18 +2052,6 @@ type multiQueryNoDelayRecordSet struct {
 	lastInsertID uint64
 }
 
-func (c *multiQueryNoDelayRecordSet) Fields() []*ast.ResultField {
-	panic("unsupported method")
-}
-
-func (c *multiQueryNoDelayRecordSet) Next(ctx context.Context, chk *chunk.Chunk) error {
-	panic("unsupported method")
-}
-
-func (c *multiQueryNoDelayRecordSet) NewChunk() *chunk.Chunk {
-	panic("unsupported method")
-}
-
 func (c *multiQueryNoDelayRecordSet) Close() error {
 	return nil
 }