expression: implement shiftLeft function pushdown (#36677)

close pingcap/tidb#36733

expression/expr_to_pb_test.go

@@ -1147,6 +1147,11 @@ func TestExprPushDownToFlash(t *testing.T) {
 	require.NoError(t, err)
 	exprs = append(exprs, function)
 
+	// ScalarFuncSig_LeftShift
+	function, err = NewFunction(mock.NewContext(), ast.LeftShift, types.NewFieldType(mysql.TypeLonglong), intColumn, intColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
 	// ReverseUTF8 test
 	function, err = NewFunction(mock.NewContext(), ast.Reverse, types.NewFieldType(mysql.TypeString), stringColumn)
 	require.NoError(t, err)

expression/expression.go

@@ -1043,7 +1043,7 @@ func scalarExprSupportedByFlash(function *ScalarFunction) bool {
 			return true
 		}
 	case
-		ast.LogicOr, ast.LogicAnd, ast.UnaryNot, ast.BitNeg, ast.Xor, ast.And, ast.Or, ast.RightShift,
+		ast.LogicOr, ast.LogicAnd, ast.UnaryNot, ast.BitNeg, ast.Xor, ast.And, ast.Or, ast.RightShift, ast.LeftShift,
 		ast.GE, ast.LE, ast.EQ, ast.NE, ast.LT, ast.GT, ast.In, ast.IsNull, ast.Like, ast.Strcmp,
 		ast.Plus, ast.Minus, ast.Div, ast.Mul, ast.Abs, ast.Mod,
 		ast.If, ast.Ifnull, ast.Case,

planner/core/integration_test.go

@@ -6978,6 +6978,39 @@ func TestAggWithJsonPushDownToTiFlash(t *testing.T) {
 	tk.MustQuery("explain select /*+ hash_agg() */  group_concat(a) from t;").CheckAt([]int{0, 2, 4}, rows)
 }
 
+func TestLeftShiftPushDownToTiFlash(t *testing.T) {
+	store, dom := testkit.CreateMockStoreAndDomain(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int, b int)")
+	tk.MustExec("insert into t values(2147483647, 32)")
+	tk.MustExec("insert into t values(12, 2)")
+	tk.MustExec("set @@tidb_allow_mpp=1; set @@tidb_enforce_mpp=1")
+	tk.MustExec("set @@tidb_isolation_read_engines = 'tiflash'")
+
+	// Create virtual tiflash replica info.
+	is := dom.InfoSchema()
+	db, exists := is.SchemaByName(model.NewCIStr("test"))
+	require.True(t, exists)
+	for _, tblInfo := range db.Tables {
+		if tblInfo.Name.L == "t" {
+			tblInfo.TiFlashReplica = &model.TiFlashReplicaInfo{
+				Count:     1,
+				Available: true,
+			}
+		}
+	}
+
+	rows := [][]interface{}{
+		{"TableReader_9", "root", "data:ExchangeSender_8"},
+		{"└─ExchangeSender_8", "mpp[tiflash]", "ExchangeType: PassThrough"},
+		{"  └─Projection_4", "mpp[tiflash]", "leftshift(test.t.a, test.t.b)->Column#4"},
+		{"    └─TableFullScan_7", "mpp[tiflash]", "keep order:false, stats:pseudo"},
+	}
+	tk.MustQuery("explain select a << b from t;").CheckAt([]int{0, 2, 4}, rows)
+}
+
 func TestIssue36609(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)