From 8ae430c633cdfa9ca39af6e4b3e2e2a7bb5dd338 Mon Sep 17 00:00:00 2001
From: Jack Yu <yusp@pingcap.com>
Date: Thu, 26 Mar 2020 11:17:38 +0800
Subject: [PATCH] *: add the tid to the schema-change related tables only when
 keys need to be locked (#15698)

---
 executor/executor.go    | 14 ++++++++------
 session/session_test.go | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/executor/executor.go b/executor/executor.go
index e4958039e719c..9e32321591408 100644
--- a/executor/executor.go
+++ b/executor/executor.go
@@ -776,12 +776,6 @@ func (e *SelectLockExec) Open(ctx context.Context) error {
 		return err
 	}
 
-	txnCtx := e.ctx.GetSessionVars().TxnCtx
-	for id := range e.Schema().TblID2Handle {
-		// This operation is only for schema validator check.
-		txnCtx.UpdateDeltaForTable(id, 0, 0, map[int64]int64{})
-	}
-
 	if len(e.Schema().TblID2Handle) > 0 && len(e.partitionedTable) > 0 {
 		e.tblID2Table = make(map[int64]table.PartitionedTable, len(e.partitionedTable))
 		for id := range e.Schema().TblID2Handle {
@@ -835,6 +829,14 @@ func (e *SelectLockExec) Next(ctx context.Context, req *chunk.Chunk) error {
 		return nil
 	}
 	lockWaitTime := e.ctx.GetSessionVars().LockWaitTimeout
+
+	if len(e.keys) > 0 {
+		// This operation is only for schema validator check.
+		for id := range e.Schema().TblID2Handle {
+			e.ctx.GetSessionVars().TxnCtx.UpdateDeltaForTable(id, 0, 0, map[int64]int64{})
+		}
+	}
+
 	return doLockKeys(ctx, e.ctx, newLockCtx(e.ctx.GetSessionVars(), lockWaitTime), e.keys...)
 }
 
diff --git a/session/session_test.go b/session/session_test.go
index 0ac2c99a84e45..7379922d26a50 100644
--- a/session/session_test.go
+++ b/session/session_test.go
@@ -1935,6 +1935,28 @@ func (s *testSchemaSuite) TestCommitWhenSchemaChanged(c *C) {
 	c.Assert(terror.ErrorEqual(err, plannercore.ErrWrongValueCountOnRow), IsTrue, Commentf("err %v", err))
 }
 
+func (s *testSchemaSuite) TestRetrySchemaChangeForEmptyChange(c *C) {
+	tk := testkit.NewTestKitWithInit(c, s.store)
+	tk1 := testkit.NewTestKitWithInit(c, s.store)
+	tk.MustExec("create table t (i int)")
+	tk.MustExec("create table t1 (i int)")
+	tk.MustExec("begin")
+	tk1.MustExec("alter table t add j int")
+	tk.MustExec("select * from t for update")
+	tk.MustExec("update t set i = -i")
+	tk.MustExec("delete from t")
+	tk.MustExec("insert into t1 values (1)")
+	tk.MustExec("commit")
+
+	tk.MustExec("begin pessimistic")
+	tk1.MustExec("alter table t add k int")
+	tk.MustExec("select * from t for update")
+	tk.MustExec("update t set i = -i")
+	tk.MustExec("delete from t")
+	tk.MustExec("insert into t1 values (1)")
+	tk.MustExec("commit")
+}
+
 func (s *testSchemaSuite) TestRetrySchemaChange(c *C) {
 	tk := testkit.NewTestKitWithInit(c, s.store)
 	tk1 := testkit.NewTestKitWithInit(c, s.store)