planner: do not cache prepared plan if optimization depends on mutabl…

…e constant (#22349) (#22353)

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

expression/expression.go

@@ -709,11 +709,18 @@ func SplitDNFItems(onExpr Expression) []Expression {
 // EvaluateExprWithNull sets columns in schema as null and calculate the final result of the scalar function.
 // If the Expression is a non-constant value, it means the result is unknown.
 func EvaluateExprWithNull(ctx sessionctx.Context, schema *Schema, expr Expression) Expression {
+	if ContainMutableConst(ctx, []Expression{expr}) {
+		ctx.GetSessionVars().StmtCtx.OptimDependOnMutableConst = true
+	}
+	return evaluateExprWithNull(ctx, schema, expr)
+}
+
+func evaluateExprWithNull(ctx sessionctx.Context, schema *Schema, expr Expression) Expression {
 	switch x := expr.(type) {
 	case *ScalarFunction:
 		args := make([]Expression, len(x.GetArgs()))
 		for i, arg := range x.GetArgs() {
-			args[i] = EvaluateExprWithNull(ctx, schema, arg)
+			args[i] = evaluateExprWithNull(ctx, schema, arg)
 		}
 		return NewFunctionInternal(ctx, x.FuncName.L, x.RetType, args...)
 	case *Column:

planner/core/common_plans.go

@@ -375,7 +375,7 @@ REBUILD:
 	e.names = names
 	e.Plan = p
 	_, isTableDual := p.(*PhysicalTableDual)
-	if !isTableDual && prepared.UseCache {
+	if !isTableDual && prepared.UseCache && !stmtCtx.OptimDependOnMutableConst {
 		cached := NewPSTMTPlanCacheValue(p, names, stmtCtx.TblInfo2UnionScan, tps)
 		preparedStmt.NormalizedPlan, preparedStmt.PlanDigest = NormalizePlan(p)
 		stmtCtx.SetPlanDigest(preparedStmt.NormalizedPlan, preparedStmt.PlanDigest)

planner/core/prepare_test.go

@@ -830,3 +830,32 @@ func (s *testPrepareSuite) TestPrepareForGroupByMultiItems(c *C) {
 	tk.MustExec(`prepare stmt2 from "select sum(b) from t group by ?, ?"`)
 	tk.MustQuery(`execute stmt2 using @v1, @v2`).Check(testkit.Rows("10"))
 }
+
+// Test for issue https://github.com/pingcap/tidb/issues/22167
+func (s *testPrepareSerialSuite) TestPrepareCacheWithJoinTable(c *C) {
+	defer testleak.AfterTest(c)()
+	store, dom, err := newStoreWithBootstrap()
+	c.Assert(err, IsNil)
+	tk := testkit.NewTestKit(c, store)
+	orgEnable := core.PreparedPlanCacheEnabled()
+	defer func() {
+		dom.Close()
+		store.Close()
+		core.SetPreparedPlanCache(orgEnable)
+	}()
+	core.SetPreparedPlanCache(true)
+	tk.Se, err = session.CreateSession4TestWithOpt(store, &session.Opt{
+		PreparedPlanCache: kvcache.NewSimpleLRUCache(100, 0.1, math.MaxUint64),
+	})
+	c.Assert(err, IsNil)
+
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists ta, tb")
+	tk.MustExec("CREATE TABLE ta(k varchar(32) NOT NULL DEFAULT ' ')")
+	tk.MustExec("CREATE TABLE tb (k varchar(32) NOT NULL DEFAULT ' ', s varchar(1) NOT NULL DEFAULT ' ')")
+	tk.MustExec("insert into ta values ('a')")
+	tk.MustExec("set @a=2, @b=1")
+	tk.MustExec(`prepare stmt from "select * from ta a left join tb b on 1 where ? = 1 or b.s is not null"`)
+	tk.MustQuery("execute stmt using @a").Check(testkit.Rows())
+	tk.MustQuery("execute stmt using @b").Check(testkit.Rows("a <nil> <nil>"))
+}

sessionctx/stmtctx/stmtctx.go

@@ -60,25 +60,26 @@ type StatementContext struct {
 
 	// IsDDLJobInQueue is used to mark whether the DDL job is put into the queue.
 	// If IsDDLJobInQueue is true, it means the DDL job is in the queue of storage, and it can be handled by the DDL worker.
-	IsDDLJobInQueue        bool
-	InInsertStmt           bool
-	InUpdateStmt           bool
-	InDeleteStmt           bool
-	InSelectStmt           bool
-	InLoadDataStmt         bool
-	InExplainStmt          bool
-	IgnoreTruncate         bool
-	IgnoreZeroInDate       bool
-	DupKeyAsWarning        bool
-	BadNullAsWarning       bool
-	DividedByZeroAsWarning bool
-	TruncateAsWarning      bool
-	OverflowAsWarning      bool
-	InShowWarning          bool
-	UseCache               bool
-	BatchCheck             bool
-	InNullRejectCheck      bool
-	AllowInvalidDate       bool
+	IsDDLJobInQueue           bool
+	InInsertStmt              bool
+	InUpdateStmt              bool
+	InDeleteStmt              bool
+	InSelectStmt              bool
+	InLoadDataStmt            bool
+	InExplainStmt             bool
+	IgnoreTruncate            bool
+	IgnoreZeroInDate          bool
+	DupKeyAsWarning           bool
+	BadNullAsWarning          bool
+	DividedByZeroAsWarning    bool
+	TruncateAsWarning         bool
+	OverflowAsWarning         bool
+	InShowWarning             bool
+	UseCache                  bool
+	BatchCheck                bool
+	InNullRejectCheck         bool
+	AllowInvalidDate          bool
+	OptimDependOnMutableConst bool
 
 	// mu struct holds variables that change during execution.
 	mu struct {