From 25edc0f22f3502b28be8c2c3019ac3641a83ddfb Mon Sep 17 00:00:00 2001
From: dongjunduo <andj4cn@gmail.com>
Date: Sat, 3 Sep 2022 23:51:46 +0800
Subject: [PATCH] expression: push down bin function to tiflash

---
 expression/expr_to_pb_test.go    |  5 +++++
 expression/expression.go         |  2 +-
 planner/core/integration_test.go | 25 +++++++++++++++++++++++++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/expression/expr_to_pb_test.go b/expression/expr_to_pb_test.go
index 03d80a14d018f..6e686c560ce14 100644
--- a/expression/expr_to_pb_test.go
+++ b/expression/expr_to_pb_test.go
@@ -1173,6 +1173,11 @@ func TestExprPushDownToFlash(t *testing.T) {
 	require.NoError(t, err)
 	exprs = append(exprs, function)
 
+	// Bin
+	function, err = NewFunction(mock.NewContext(), ast.Bin, types.NewFieldType(mysql.TypeString), intColumn)
+	require.NoError(t, err)
+	exprs = append(exprs, function)
+
 	// Elt
 	function, err = NewFunction(mock.NewContext(), ast.Elt, types.NewFieldType(mysql.TypeString), intColumn, stringColumn)
 	require.NoError(t, err)
diff --git a/expression/expression.go b/expression/expression.go
index 05a5b0a09d294..a69c842a594a0 100644
--- a/expression/expression.go
+++ b/expression/expression.go
@@ -1161,7 +1161,7 @@ func scalarExprSupportedByFlash(function *ScalarFunction) bool {
 		}
 	case ast.IsTruthWithNull, ast.IsTruthWithoutNull, ast.IsFalsity:
 		return true
-	case ast.Hex:
+	case ast.Hex, ast.Bin:
 		return true
 	case ast.GetFormat:
 		return true
diff --git a/planner/core/integration_test.go b/planner/core/integration_test.go
index 075972aa23a01..17b8c7b25f4db 100644
--- a/planner/core/integration_test.go
+++ b/planner/core/integration_test.go
@@ -7060,6 +7060,31 @@ func TestHexIntOrStrPushDownToTiFlash(t *testing.T) {
 	tk.MustQuery("explain select hex(b) from t;").CheckAt([]int{0, 2, 4}, rows)
 }
 
+func TestBinPushDownToTiFlash(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);")
+	tk.MustExec("insert into t values(1);")
+	tk.MustExec("set @@tidb_allow_mpp=1; set @@tidb_enforce_mpp=1;")
+	tk.MustExec("set @@tidb_isolation_read_engines = 'tiflash'")
+
+	tbl, err := dom.InfoSchema().TableByName(model.CIStr{O: "test", L: "test"}, model.CIStr{O: "t", L: "t"})
+	require.NoError(t, err)
+	// Set the hacked TiFlash replica for explain tests.
+	tbl.Meta().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]", "bin(test.t.a)->Column#3"},
+		{"    └─TableFullScan_7", "mpp[tiflash]", "keep order:false, stats:pseudo"},
+	}
+	tk.MustQuery("explain select bin(a) from t;").CheckAt([]int{0, 2, 4}, rows)
+}
+
 func TestEltPushDownToTiFlash(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)