cherry pick pingcap#24049 to release-5.0

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>
ti-srebot · Apr 16, 2021 · 2bd8b50 · 2bd8b50
1 parent 672d649
commit 2bd8b50
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Showing 5 changed files with 25 additions and 5 deletions.
diff --git a/cmd/explaintest/r/explain_easy.result b/cmd/explaintest/r/explain_easy.result
@@ -387,7 +387,7 @@ Projection	5.00	root		Column#17
         └─Selection	2.40	cop[tikv]		eq(3, test.t.a)
           └─IndexRangeScan	3.00	cop[tikv]	table:t1, index:idx(b)	range:[3,3], keep order:true
 drop table if exists t;
-create table t(a int unsigned);
+create table t(a int unsigned not null);
 explain format = 'brief' select t.a = '123455' from t;
 id	estRows	task	access object	operator info
 Projection	10000.00	root		eq(test.t.a, 123455)->Column#3

diff --git a/cmd/explaintest/t/explain_easy.test b/cmd/explaintest/t/explain_easy.test
@@ -71,7 +71,7 @@ explain format = 'brief' select t.c in (select count(*) from t s left join t t1
 explain format = 'brief' select t.c in (select count(*) from t s right join t t1 on s.a = t1.a where 3 = t.a and t1.b = 3) from t;
 
 drop table if exists t;
-create table t(a int unsigned);
+create table t(a int unsigned not null);
 explain format = 'brief' select t.a = '123455' from t;
 explain format = 'brief' select t.a > '123455' from t;
 explain format = 'brief' select t.a != '123455' from t;

diff --git a/expression/builtin_compare.go b/expression/builtin_compare.go
@@ -1354,7 +1354,10 @@ func (c *compareFunctionClass) refineArgs(ctx sessionctx.Context, args []Express
 		if !isExceptional || (isExceptional && mysql.HasNotNullFlag(arg0Type.Flag)) {
 			finalArg1 = arg1
 		}
-		if isExceptional && arg1.GetType().EvalType() == types.ETInt && mysql.HasNotNullFlag(arg0Type.Flag) {
+		// TODO if the plan doesn't care about whether the result of the function is null or false, we don't need
+		// to check the NotNullFlag, then more optimizations can be enabled.
+		isExceptional = isExceptional && mysql.HasNotNullFlag(arg0Type.Flag)
+		if isExceptional && arg1.GetType().EvalType() == types.ETInt {
 			// Judge it is inf or -inf
 			// For int:
 			//			inf:  01111111 & 1 == 1
@@ -1375,7 +1378,10 @@ func (c *compareFunctionClass) refineArgs(ctx sessionctx.Context, args []Express
 		if !isExceptional || (isExceptional && mysql.HasNotNullFlag(arg1Type.Flag)) {
 			finalArg0 = arg0
 		}
-		if isExceptional && arg0.GetType().EvalType() == types.ETInt && mysql.HasNotNullFlag(arg1Type.Flag) {
+		// TODO if the plan doesn't care about whether the result of the function is null or false, we don't need
+		// to check the NotNullFlag, then more optimizations can be enabled.
+		isExceptional = isExceptional && mysql.HasNotNullFlag(arg1Type.Flag)
+		if isExceptional && arg0.GetType().EvalType() == types.ETInt {
 			if arg0.Value.GetInt64()&1 == 1 {
 				isNegativeInfinite = true
 			} else {

diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -9084,3 +9084,17 @@ func (s *testIntegrationSuite) TestIssue23889(c *C) {
 	tk.MustQuery("SELECT ( test_decimal . `col_decimal` , test_decimal . `col_decimal` )  IN ( select * from test_t ) as field1 FROM  test_decimal;").Check(
 		testkit.Rows("<nil>", "0"))
 }
+
+func (s *testIntegrationSuite) TestRefineArgNullValues(c *C) {
+	defer s.cleanEnv(c)
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("create table t(id int primary key, a int)")
+	tk.MustExec("create table s(a int)")
+	tk.MustExec("insert into s values(1),(2)")
+
+	tk.MustQuery("select t.id = 1.234 from t right join s on t.a = s.a").Check(testkit.Rows(
+		"<nil>",
+		"<nil>",
+	))
+}
diff --git a/planner/core/integration_test.go b/planner/core/integration_test.go
@@ -1071,7 +1071,7 @@ func (s *testIntegrationSuite) TestPartitionPruningForInExpr(c *C) {
 
 	tk.MustExec("use test")
 	tk.MustExec("drop table if exists t")
-	tk.MustExec("create table t(a int(11), b int) partition by range (a) (partition p0 values less than (4), partition p1 values less than(10), partition p2 values less than maxvalue);")
+	tk.MustExec("create table t(a int(11) not null, b int) partition by range (a) (partition p0 values less than (4), partition p1 values less than(10), partition p2 values less than maxvalue);")
 	tk.MustExec("insert into t values (1, 1),(10, 10),(11, 11)")
 
 	var input []string