expression: Add cast as json push down support for tiflash (#48550)

close #48551
pingcap · Nov 28, 2023 · d0feede · d0feede
1 parent ccbd1b5
commit d0feede
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diff --git a/pkg/expression/expr_to_pb_test.go b/pkg/expression/expr_to_pb_test.go
@@ -1291,6 +1291,44 @@ func TestExprPushDownToFlash(t *testing.T) {
 	require.NoError(t, err)
 	exprs = append(exprs, function)
 
+	// CastIntAsJson
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), intColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
+	// CastRealAsJson
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), realColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
+	// CastDecimalAsJson
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), decimalColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
+	// CastStringAsJson
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), stringColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), binaryStringColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
+	// CastTimeAsJson
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), datetimeColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
+	// CastDurationAsJson
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), durationColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
+	// CastJsonAsJson
+	function, err = NewFunction(mock.NewContext(), ast.Cast, types.NewFieldType(mysql.TypeJSON), jsonColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
 	pushed, remained = PushDownExprs(ctx, exprs, client, kv.TiFlash)
 	require.Len(t, pushed, len(exprs))
 	require.Len(t, remained, 0)

diff --git a/pkg/expression/expression.go b/pkg/expression/expression.go
@@ -1237,6 +1237,9 @@ func scalarExprSupportedByFlash(function *ScalarFunction) bool {
 			return function.GetArgs()[0].GetType().GetType() != mysql.TypeYear
 		case tipb.ScalarFuncSig_CastTimeAsDuration:
 			return retType.GetType() == mysql.TypeDuration
+		case tipb.ScalarFuncSig_CastIntAsJson, tipb.ScalarFuncSig_CastRealAsJson, tipb.ScalarFuncSig_CastDecimalAsJson, tipb.ScalarFuncSig_CastStringAsJson,
+			tipb.ScalarFuncSig_CastTimeAsJson, tipb.ScalarFuncSig_CastDurationAsJson, tipb.ScalarFuncSig_CastJsonAsJson:
+			return true
 		}
 	case ast.DateAdd, ast.AddDate:
 		switch function.Function.PbCode() {