planner: add more test cases for instance plan cache (#56110)

ref #54057

pkg/planner/core/casetest/instanceplancache/BUILD.bazel

@@ -6,8 +6,9 @@ go_test(
     srcs = [
         "dml_test.go",
         "main_test.go",
+        "others_test.go",
     ],
     flaky = True,
-    shard_count = 3,
+    shard_count = 9,
     deps = ["//pkg/testkit"],
 )

pkg/planner/core/casetest/instanceplancache/others_test.go

@@ -0,0 +1,233 @@
+// Copyright 2024 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package instanceplancache
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/pingcap/tidb/pkg/testkit"
+)
+
+func TestInstancePlanCacheVars(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`create table t (a int, b int)`)
+
+	// check default values
+	tk.MustQuery(`select @@tidb_enable_instance_plan_cache`).Check(testkit.Rows("0"))
+	tk.MustQuery(`select @@tidb_instance_plan_cache_max_size`).Check(testkit.Rows("104857600"))
+	tk.MustQuery(`select @@tidb_instance_plan_cache_reserved_percentage`).Check(testkit.Rows("0.1"))
+	tk.MustExec(`set global tidb_enable_instance_plan_cache=1`)
+	tk.MustQuery(`select @@tidb_enable_instance_plan_cache`).Check(testkit.Rows("1"))
+
+	// check invalid values
+	tk.MustExec(`set global tidb_enable_instance_plan_cache=1`)
+	tk.MustQuery(`select @@tidb_enable_instance_plan_cache`).Check(testkit.Rows("1"))
+	tk.MustExecToErr(`set global tidb_instance_plan_cache_max_size=-1`)
+	tk.MustExecToErr(`set global tidb_instance_plan_cache_max_size=-1111111111111`)
+	tk.MustExecToErr(`set global tidb_instance_plan_cache_max_size=dslfj`)
+	tk.MustExec(`set global tidb_instance_plan_cache_max_size=123456`)
+	tk.MustQuery(`select @@tidb_instance_plan_cache_max_size`).Check(testkit.Rows("123456"))
+	tk.MustExec(`set global tidb_instance_plan_cache_reserved_percentage=-1`)
+	tk.MustQuery(`show warnings`).Check(testkit.Rows(`Warning 1292 Truncated incorrect tidb_instance_plan_cache_reserved_percentage value: '-1'`))
+	tk.MustExec(`set global tidb_instance_plan_cache_reserved_percentage=1.1100`)
+	tk.MustQuery(`show warnings`).Check(testkit.Rows(`Warning 1292 Truncated incorrect tidb_instance_plan_cache_reserved_percentage value: '1.1100'`))
+	tk.MustExec(`set global tidb_instance_plan_cache_reserved_percentage=0.1`)
+	tk.MustQuery(`show warnings`).Check(testkit.Rows())
+}
+
+func TestInstancePlanCacheBinding(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`create table t1 (a int, b int, key(b))`)
+	tk.MustExec(`create table t2 (a int, b int, key(b))`)
+	tk.MustExec(`create table t3 (a int, b int, key(b))`)
+	tk.MustExec(`set global tidb_enable_instance_plan_cache=1`)
+	tk.MustQuery(`select @@tidb_enable_instance_plan_cache`).Check(testkit.Rows("1"))
+
+	// normal binding
+	tk.MustExec(`prepare st from 'select * from t1 where a=?'`)
+	tk.MustExec(`set @a=1`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+	tk.MustExec(`create binding using select /*+ use_index(t1, b) */ * from t1 where a=2`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0")) // can't hit due to the binding
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1")) // hit the bound plan
+
+	// cross-db binding
+	tk.MustExec(`set @@tidb_opt_enable_fuzzy_binding=1`)
+	tk.MustExec(`prepare st from 'select * from t2 where a=?'`)
+	tk.MustExec(`set @a=1`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+	tk.MustExec(`create binding using select /*+ use_index(t2, b) */ * from *.t2 where a=2`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0")) // can't hit due to the binding
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1")) // hit the bound plan
+
+	// ignore-plan-cache hint
+	tk.MustExec(`prepare st from 'select /*+ ignore_plan_cache() */ * from t3 where b=?'`)
+	tk.MustExec(`set @a=1`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+
+	// ignore-plan-cache hint with binding
+	tk.MustExec(`prepare st from 'select * from t3 where a=?'`)
+	tk.MustExec(`set @a=1`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+	tk.MustExec(`create binding using select /*+ ignore_plan_cache() */ * from t3 where a=2`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+}
+
+func TestInstancePlanCacheReason(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`create table t1 (a int, b int, key(b))`)
+	tk.MustExec(`create table t2 (a int, b int, key(b))`)
+	tk.MustExec(`set global tidb_enable_instance_plan_cache=1`)
+	tk.MustQuery(`select @@tidb_enable_instance_plan_cache`).Check(testkit.Rows("1"))
+
+	tk.MustExec(`prepare st from 'select * from t1 where t1.a > (select 1 from t2 where t2.b<1)'`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`show warnings`).Check(testkit.Rows(
+		"Warning 1105 skip prepared plan-cache: query has uncorrelated sub-queries is un-cacheable"))
+
+	tk.MustExec(`prepare st from 'select * from t1 limit ?'`)
+	tk.MustExec(`set @a=1000000`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`show warnings`).Check(testkit.Rows(
+		"Warning 1105 skip prepared plan-cache: limit count is too large"))
+
+	tk.MustExec(`prepare st from 'select b from t1 where b < ?'`)
+	tk.MustExec(`set @a='123'`)
+	tk.MustExec(`execute st using @a`)
+	tk.MustQuery(`show warnings`).Check(testkit.Rows(
+		"Warning 1105 skip prepared plan-cache: '123' may be converted to INT"))
+}
+
+func TestInstancePlanCacheStaleRead(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`set global tidb_enable_instance_plan_cache=1`)
+	tk.MustExec(`create table t (a int)`)
+	time.Sleep(time.Second)
+	ts0 := tk.MustQuery(`select now()`).Rows()[0][0].(string)
+	time.Sleep(time.Second)
+	tk.MustExec(`insert into t values (1)`)
+	time.Sleep(time.Second)
+	ts1 := tk.MustQuery(`select now()`).Rows()[0][0].(string)
+	time.Sleep(time.Second)
+	tk.MustExec(`insert into t values (2), (3)`)
+	time.Sleep(time.Second)
+	ts2 := tk.MustQuery(`select now()`).Rows()[0][0].(string)
+
+	// as-of-timestamp statements
+	tk.MustExecToErr(`prepare st from 'select * from t as of timestamp ?'`) // not supported yet
+
+	tk.MustExec(fmt.Sprintf(`prepare st from 'select * from t as of timestamp "%v"'`, ts0))
+	tk.MustQuery(`execute st`).Sort().Check(testkit.Rows())
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustQuery(`execute st`).Sort().Check(testkit.Rows())
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+
+	tk.MustExec(fmt.Sprintf(`prepare st from 'select * from t as of timestamp "%v"'`, ts1))
+	tk.MustQuery(`execute st`).Sort().Check(testkit.Rows("1"))
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustQuery(`execute st`).Sort().Check(testkit.Rows("1"))
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+
+	tk.MustExec(fmt.Sprintf(`prepare st from 'select * from t as of timestamp "%v"'`, ts2))
+	tk.MustQuery(`execute st`).Sort().Check(testkit.Rows("1", "2", "3"))
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustQuery(`execute st`).Sort().Check(testkit.Rows("1", "2", "3"))
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+}
+
+func TestInstancePlanCacheInTxn(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`set global tidb_enable_instance_plan_cache=1`)
+	tk.MustExec(`create table t (a int)`)
+	tk.MustExec(`prepare st from 'select * from t'`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+
+	tk.MustExec(`begin`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0")) // can't hit
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+	tk.MustExec(`insert into t values (1)`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0")) // dirty-data
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+	tk.MustExec(`rollback`)
+
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+
+	tk.MustExec(`begin`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+	tk.MustExec(`rollback`)
+}
+
+func TestInstancePlanCacheSchemaChange(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`set global tidb_enable_instance_plan_cache=1`)
+	tk.MustExec(`create table t (a int)`)
+	tk.MustExec(`prepare st from 'select * from t'`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0"))
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+
+	tk.MustExec(`alter table t add column b int`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0")) // due to DDL
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+
+	tk.MustExec(`alter table t drop column b`)
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("0")) // due to DDL
+	tk.MustExec(`execute st`)
+	tk.MustQuery(`select @@last_plan_from_cache`).Check(testkit.Rows("1"))
+}

pkg/sessionctx/variable/sysvar.go

@@ -1356,6 +1356,9 @@ var defaultSysVars = []*SysVar{
 		},
 		SetGlobal: func(_ context.Context, s *SessionVars, val string) error {
 			v := tidbOptFloat64(val, DefTiDBInstancePlanCacheReservedPercentage)
+			if v < 0 || v > 1 {
+				return errors.Errorf("invalid tidb_instance_plan_cache_reserved_percentage value %s", val)
+			}
 			InstancePlanCacheReservedPercentage.Store(v)
 			return nil
 		}},
@@ -1365,11 +1368,8 @@ var defaultSysVars = []*SysVar{
 		},
 		SetGlobal: func(_ context.Context, s *SessionVars, val string) error {
 			v, str := parseByteSize(val)
-			if str == "" {
-				v = uint64(TidbOptInt64(val, int64(DefTiDBInstancePlanCacheMaxMemSize)))
-			}
-			if v < 0 {
-				return errors.New("tidb_instance_plan_cache_max_mem_size must be a non-negative integer")
+			if str == "" || v < 0 {
+				return errors.Errorf("invalid tidb_instance_plan_cache_max_mem_size value %s", val)
 			}
 			InstancePlanCacheMaxMemSize.Store(int64(v))
 			return nil