plan: fix convert to physical plan, when there are multiple index ranges (#1532)

plan/match_property.go

@@ -14,8 +14,9 @@
 package plan
 
 import (
-	"github.com/pingcap/tidb/util/types"
 	"math"
+
+	"github.com/pingcap/tidb/util/types"
 )
 
 // matchProperty implements PhysicalPlan matchProperty interface.

plan/new_plan_test.go

@@ -362,6 +362,14 @@ func (s *testPlanSuite) TestRefine(c *C) {
 			sql:  "select a from t where c <= 5 and c >= 3 and d = 1",
 			best: "Index(t.c_d_e)[[3,5]]->Selection->Projection",
 		},
+		{
+			sql:  "select a from t where c = 1 or c = 2 or c = 3",
+			best: "Index(t.c_d_e)[[1,1] [2,2] [3,3]]->Projection",
+		},
+		{
+			sql:  "select a from t where c = 1 or c = 2 or c = 3 or c = 4 or c = 5",
+			best: "Table(t)->Selection->Projection",
+		},
 	}
 	for _, ca := range cases {
 		comment := Commentf("for %s", ca.sql)

plan/physical_plan_builder.go

@@ -14,13 +14,14 @@
 package plan
 
 import (
+	"math"
+
 	"github.com/juju/errors"
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/plan/statistics"
 	"github.com/pingcap/tidb/util/types"
-	"math"
 )
 
 const (
@@ -47,7 +48,15 @@ func getRowCountByIndexRange(table *statistics.Table, indexRange *IndexRange, in
 			rowCount, err = table.Columns[offset].LessRowCount(r)
 			rowCount = table.Count - rowCount
 		} else {
-			rowCount, err = table.Columns[offset].BetweenRowCount(l, r)
+			compare, err1 := l.CompareDatum(r)
+			if err1 != nil {
+				return 0, errors.Trace(err1)
+			}
+			if compare == 0 {
+				rowCount, err = table.Columns[offset].EqualRowCount(l)
+			} else {
+				rowCount, err = table.Columns[offset].BetweenRowCount(l, r)
+			}
 		}
 		if err != nil {
 			return 0, errors.Trace(err)