planner: check the ignore-plan-cache hint in insert-stmt (#40080)

executor/seqtest/prepared_test.go

@@ -495,14 +495,14 @@ func TestPreparedInsert(t *testing.T) {
  err = counter.Write(pb)
  require.NoError(t, err)
  hit := pb.GetCounter().GetValue()
- require.Equal(t, float64(1), hit)
+ require.Equal(t, float64(0), hit)
  }
  tk.MustExec(`set @a=3,@b=3; execute stmt_insert using @a, @b;`)
  if flag {
  err = counter.Write(pb)
  require.NoError(t, err)
  hit := pb.GetCounter().GetValue()
- require.Equal(t, float64(2), hit)
+ require.Equal(t, float64(0), hit)
  }
 
  result := tk.MustQuery("select id, c1 from prepare_test where id = ?", 1)
@@ -518,21 +518,21 @@ func TestPreparedInsert(t *testing.T) {
  err = counter.Write(pb)
  require.NoError(t, err)
  hit := pb.GetCounter().GetValue()
- require.Equal(t, float64(2), hit)
+ require.Equal(t, float64(0), hit)
  }
  tk.MustExec(`set @a=2; execute stmt_insert_select using @a;`)
  if flag {
  err = counter.Write(pb)
  require.NoError(t, err)
  hit := pb.GetCounter().GetValue()
- require.Equal(t, float64(3), hit)
+ require.Equal(t, float64(1), hit)
  }
  tk.MustExec(`set @a=3; execute stmt_insert_select using @a;`)
  if flag {
  err = counter.Write(pb)
  require.NoError(t, err)
  hit := pb.GetCounter().GetValue()
- require.Equal(t, float64(4), hit)
+ require.Equal(t, float64(2), hit)
  }
 
  result = tk.MustQuery("select id, c1 from prepare_test where id = ?", 101)

planner/core/cacheable_checker.go

@@ -87,6 +87,19 @@ func (checker *cacheableChecker) Enter(in ast.Node) (out ast.Node, skipChildren
  return in, true
  }
  }
+ case *ast.InsertStmt:
+ if node.Select == nil {
+ // do not cache insert-values-stmt like 'insert into t values (...)' since
+ // no performance benefit and to save memory.
+ checker.cacheable = false
+ return in, true
+ }
+ for _, hints := range node.TableHints {
+ if hints.HintName.L == HintIgnorePlanCache {
+ checker.cacheable = false
+ return in, true
+ }
+ }
  case *ast.VariableExpr, *ast.ExistsSubqueryExpr, *ast.SubqueryExpr:
  checker.cacheable = false
  return in, true

planner/core/cacheable_checker_test.go

@@ -27,6 +27,30 @@ import (
  "github.com/stretchr/testify/require"
 )
 
+func TestIgnoreInsertStmt(t *testing.T) {
+ store, clean := testkit.CreateMockStore(t)
+ defer clean()
+ tk := testkit.NewTestKit(t, store)
+ tk.MustExec("use test")
+ tk.MustExec("create table t (a int)")
+
+ // do not cache native insert-stmt
+ tk.MustExec("prepare st from 'insert into t values (1)'")
+ tk.MustExec("execute st")
+ tk.MustExec("execute st")
+ tk.MustQuery("select @@last_plan_from_cache").Check(testkit.Rows("0"))
+
+ // ignore-hint in insert-stmt can work
+ tk.MustExec("prepare st from 'insert into t select * from t'")
+ tk.MustExec("execute st")
+ tk.MustExec("execute st")
+ tk.MustQuery("select @@last_plan_from_cache").Check(testkit.Rows("1"))
+ tk.MustExec("prepare st from 'insert /*+ ignore_plan_cache() */ into t select * from t'")
+ tk.MustExec("execute st")
+ tk.MustExec("execute st")
+ tk.MustQuery("select @@last_plan_from_cache").Check(testkit.Rows("0"))
+}
+
 func TestCacheable(t *testing.T) {
  store, clean := testkit.CreateMockStore(t)
  defer clean()
@@ -52,7 +76,9 @@ func TestCacheable(t *testing.T) {
 
  tableRefsClause := &ast.TableRefsClause{TableRefs: &ast.Join{Left: &ast.TableSource{Source: tbl}}}
  // test InsertStmt
- stmt = &ast.InsertStmt{Table: tableRefsClause}
+ stmt = &ast.InsertStmt{Table: tableRefsClause} // insert-values-stmt
+ require.False(t, core.Cacheable(stmt, is))
+ stmt = &ast.InsertStmt{Table: tableRefsClause, Select: &ast.SelectStmt{}} // insert-select-stmt
  require.True(t, core.Cacheable(stmt, is))
 
  // test DeleteStmt