planner: do not cache the tableDual plan (#31290) (#31353)

close #31280
pingcap · Feb 23, 2022 · c002791 · c002791
1 parent 22f33e7
commit c002791
Show file tree

Hide file tree

Showing 5 changed files with 160 additions and 49 deletions.
diff --git a/executor/prepared_test.go b/executor/prepared_test.go
@@ -775,9 +775,10 @@ func (s *testSerialSuite) TestIssue28782(c *C) {
 
 	tk.MustQuery("execute stmt using @a;").Check(testkit.Rows("1"))
 	tk.MustQuery("execute stmt using @b;").Check(testkit.Rows("0"))
-	tk.MustQuery("select @@last_plan_from_cache;").Check(testkit.Rows("1"))
+	// TODO(Reminiscent): Support cache more tableDual plan.
+	tk.MustQuery("select @@last_plan_from_cache;").Check(testkit.Rows("0"))
 	tk.MustQuery("execute stmt using @c;").Check(testkit.Rows("0"))
-	tk.MustQuery("select @@last_plan_from_cache;").Check(testkit.Rows("1"))
+	tk.MustQuery("select @@last_plan_from_cache;").Check(testkit.Rows("0"))
 }
 
 func (s *testSerialSuite) TestIssue29850(c *C) {
@@ -1071,7 +1072,7 @@ func (s *testSerialSuite) TestPreparePlanCache4Function(c *C) {
 	tk.MustExec("set @a = 1, @b = null;")
 	tk.MustQuery("execute stmt using @a;").Check(testkit.Rows("1"))
 	tk.MustQuery("execute stmt using @b;").Check(testkit.Rows("0"))
-	tk.MustQuery("select @@last_plan_from_cache;").Check(testkit.Rows("1"))
+	tk.MustQuery("select @@last_plan_from_cache;").Check(testkit.Rows("0"))
 
 	tk.MustExec("drop table if exists t;")
 	tk.MustExec("create table t(a int);")