partition: fix partitioning pruning includes an impossible partition (#…

…42356)

close #42273

planner/core/integration_partition_test.go

@@ -1176,7 +1176,7 @@ func TestRangeMultiColumnsPruning(t *testing.T) {
 	// WAS HERE, Why is the start return TRUE making this to work and FALSE disapear?
 	tk.MustQuery(`select a,b,c from t where a = 0 AND c = "Wow"`).Check(testkit.Rows("0 2020-01-01 00:00:00 Wow"))
 	tk.MustQuery(`explain format = 'brief' select a,b,c from t where a = 0 AND c = "Wow"`).Check(testkit.Rows(
-		`IndexReader 0.50 root partition:p3,p4,p5,p6,p7,p8 index:Selection`,
+		`IndexReader 0.50 root partition:p3,p4,p5,p6,p7 index:Selection`,
 		`└─Selection 0.50 cop[tikv]  eq(rcolumnsmulti.t.c, "Wow")`,
 		`  └─IndexRangeScan 1.00 cop[tikv] table:t, index:a(a, b, c) range:[0,0], keep order:false`))
 }
@@ -1284,11 +1284,11 @@ func TestRangeColumnsExpr(t *testing.T) {
 		"└─Selection 0.05 cop[tikv]  eq(rce.t.a, 5), eq(rce.t.c, 3)",
 		"  └─TableFullScan 21.00 cop[tikv] table:t keep order:false"))
 	tk.MustQuery(`explain format = 'brief' select * from t where a = 4 and c = 3`).Check(testkit.Rows(
-		"TableReader 0.43 root partition:p1,p2,p3,p4,p5,p6,p7,p8,p9 data:Selection",
+		"TableReader 0.43 root partition:p1,p2,p3,p4,p5,p6,p7,p8 data:Selection",
 		"└─Selection 0.43 cop[tikv]  eq(rce.t.a, 4), eq(rce.t.c, 3)",
 		"  └─TableFullScan 21.00 cop[tikv] table:t keep order:false"))
 	tk.MustQuery(`explain format = 'brief' select * from t where a in (4,14) and c = 3`).Check(testkit.Rows(
-		"TableReader 0.57 root partition:p1,p2,p3,p4,p5,p6,p7,p8,p9,p11,p12 data:Selection",
+		"TableReader 0.57 root partition:p1,p2,p3,p4,p5,p6,p7,p8,p11,p12 data:Selection",
 		"└─Selection 0.57 cop[tikv]  eq(rce.t.c, 3), in(rce.t.a, 4, 14)",
 		"  └─TableFullScan 21.00 cop[tikv] table:t keep order:false"))
 	tk.MustQuery(`explain format = 'brief' select * from t where a in (4,14) and b in (null,10)`).Check(testkit.Rows(

planner/core/partition_pruner_test.go

@@ -454,6 +454,32 @@ func TestIssue33231(t *testing.T) {
 		Check(testkit.Rows("6 beautiful curran 6 vigorous rhodes", "7 affectionate curie 7 sweet aryabhata", "7 epic kalam 7 sweet aryabhata"))
 }
 
+func TestIssue42273(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("create database issue42273")
+	defer tk.MustExec("drop database issue42273")
+
+	tk.MustExec("use issue42273")
+	tk.MustExec(`CREATE TABLE t(a tinyint unsigned,  b tinyint unsigned) PARTITION BY RANGE COLUMNS (a,b)(
+			PARTITION p0 VALUES LESS THAN (10,255),
+			PARTITION p1 VALUES LESS THAN (20,MAXVALUE),
+			PARTITION p2 VALUES LESS THAN (30,255),
+			PARTITION p3 VALUES LESS THAN (MAXVALUE, 0))`)
+	tk.MustExec("insert into t values(20, 30)")
+	tk.MustExec(`analyze table t`) // Creates global stats for the table and enables the dynamic pruning
+	tk.MustQuery(`explain format='brief' select * from t where a = 20`).Check(testkit.Rows(
+		"TableReader 1.00 root partition:p1 data:Selection",
+		"└─Selection 1.00 cop[tikv]  eq(issue42273.t.a, 20)",
+		"  └─TableFullScan 1.00 cop[tikv] table:t keep order:false"))
+	tk.MustQuery(`explain format='brief' select * from t where a > 10 and a <= 20`).Check(testkit.Rows(
+		"TableReader 1.00 root partition:p1 data:Selection",
+		"└─Selection 1.00 cop[tikv]  gt(issue42273.t.a, 10), le(issue42273.t.a, 20)",
+		"  └─TableFullScan 1.00 cop[tikv] table:t keep order:false"))
+	tk.MustQuery(`select * from t where a = 20`).Check(testkit.Rows("20 30"))
+	tk.MustQuery(`select * from t where a > 10 and a <= 20`).Check(testkit.Rows("20 30"))
+}
+
 func TestIssue43459(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)

planner/core/partition_pruning_test.go

@@ -491,7 +491,7 @@ func TestPartitionRangeColumnsForExpr(t *testing.T) {
 		{"c = 3", partitionRangeOR{{0, len(partDefs)}}},
 		{"b > 3 AND c = 3", partitionRangeOR{{0, len(partDefs)}}},
 		{"a = 5 AND c = 3", partitionRangeOR{{9, 10}}},
-		{"a = 4 AND c = 3", partitionRangeOR{{1, 10}}},
+		{"a = 4 AND c = 3", partitionRangeOR{{1, 9}}},
 		{"b > 3", partitionRangeOR{{0, len(partDefs)}}},
 		{"a > 3", partitionRangeOR{{1, len(partDefs)}}},
 		{"a < 3", partitionRangeOR{{0, 1}}},

planner/core/rule_partition_processor.go

@@ -1147,6 +1147,14 @@ func maxCmp(ctx sessionctx.Context, hiVal []types.Datum, columnsPruner *rangeCol
 				return false
 			}
 		}
+		// All hiVal == columnsPruner.lessThan
+		if len(hiVal) < len(columnsPruner.lessThan[i]) {
+			// Not all columns given
+			if columnsPruner.lessThan[i][len(hiVal)] == nil {
+				// MAXVALUE
+				return true
+			}
+		}
 		// if point is included, then false, due to LESS THAN
 		return hiExclude
 	}