ranger: add a more common method to calc range. (pingcap#3489)

expression/column.go

@@ -245,3 +245,41 @@ func Column2Exprs(cols []*Column) []Expression {
 	}
 	return result
 }
+
+// ColInfo2Col finds the corresponding column of the ColumnInfo in a column slice.
+func ColInfo2Col(cols []*Column, col *model.ColumnInfo) *Column {
+	for _, c := range cols {
+		if c.ColName.L == col.Name.L {
+			return c
+		}
+	}
+	return nil
+}
+
+// indexCol2Col finds the corresponding column of the IndexColumn in a column slice.
+func indexCol2Col(cols []*Column, col *model.IndexColumn) *Column {
+	for _, c := range cols {
+		if c.ColName.L == col.Name.L {
+			return c
+		}
+	}
+	return nil
+}
+
+// IndexInfo2Cols gets the corresponding []*Column of the indexInfo's []*IndexColumn,
+// together with a []int containing their lengths.
+// If this index has three IndexColumn that the 1st and 3rd IndexColumn has corresponding *Column,
+// the return value will be only the 1st corresponding *Column and its length.
+func IndexInfo2Cols(cols []*Column, index *model.IndexInfo) ([]*Column, []int) {
+	retCols := make([]*Column, 0, len(index.Columns))
+	lengths := make([]int, 0, len(index.Columns))
+	for _, c := range index.Columns {
+		col := indexCol2Col(cols, c)
+		if col == nil {
+			return retCols, lengths
+		}
+		retCols = append(retCols, col)
+		lengths = append(lengths, c.Length)
+	}
+	return retCols, lengths
+}

model/model.go

@@ -135,6 +135,17 @@ func (t *TableInfo) GetPkName() CIStr {
 	return CIStr{}
 }
 
+// GetPkColInfo gets the ColumnInfo of pk if exists.
+// Make sure PkIsHandle checked before call this method.
+func (t *TableInfo) GetPkColInfo() *ColumnInfo {
+	for _, colInfo := range t.Columns {
+		if mysql.HasPriKeyFlag(colInfo.Flag) {
+			return colInfo
+		}
+	}
+	return nil
+}
+
 // ColumnIsInIndex checks whether c is included in any indices of t.
 func (t *TableInfo) ColumnIsInIndex(c *ColumnInfo) bool {
 	for _, index := range t.Indices {

plan/new_physical_plan_builder.go

@@ -17,6 +17,7 @@ import (
 	"math"
 
 	"github.com/juju/errors"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/infoschema"
@@ -684,22 +685,27 @@ func (p *DataSource) convertToIndexScan(prop *requiredProp, idx *model.IndexInfo
 	statsTbl := p.statisticTable
 	rowCount := float64(statsTbl.Count)
 	sc := p.ctx.GetSessionVars().StmtCtx
+	idxCols, colLengths := expression.IndexInfo2Cols(p.Schema().Columns, idx)
+	is.Ranges = ranger.FullIndexRange()
 	if len(p.pushedDownConds) > 0 {
 		conds := make([]expression.Expression, 0, len(p.pushedDownConds))
 		for _, cond := range p.pushedDownConds {
 			conds = append(conds, cond.Clone())
 		}
-		is.AccessCondition, is.filterCondition, is.accessEqualCount, is.accessInAndEqCount = ranger.DetachIndexScanConditions(conds, idx)
-		is.Ranges, err = ranger.BuildIndexRange(sc, is.Table, is.Index, is.accessInAndEqCount, is.AccessCondition)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		rowCount, err = statsTbl.GetRowCountByIndexRanges(sc, is.Index.ID, is.Ranges)
-		if err != nil {
-			return nil, errors.Trace(err)
+		if len(idxCols) > 0 {
+			var ranges []types.Range
+			ranges, is.AccessCondition, is.filterCondition, err = ranger.BuildRange(sc, conds, ranger.IndexRangeType, idxCols, colLengths)
+			if err != nil {
+				return nil, errors.Trace(err)
+			}
+			is.Ranges = ranger.Ranges2IndexRanges(ranges)
+			rowCount, err = statsTbl.GetRowCountByIndexRanges(sc, is.Index.ID, is.Ranges)
+			if err != nil {
+				return nil, errors.Trace(err)
+			}
+		} else {
+			is.filterCondition = conds
 		}
-	} else {
-		is.Ranges = ranger.FullIndexRange()
 	}
 	cop := &copTask{
 		cnt:       rowCount,
@@ -739,7 +745,7 @@ func (p *DataSource) convertToIndexScan(prop *requiredProp, idx *model.IndexInfo
 			if col.Name.L == prop.cols[0].ColName.L {
 				matchProperty = matchIndicesProp(idx.Columns[i:], prop.cols)
 				break
-			} else if i >= is.accessEqualCount {
+			} else if i >= len(is.AccessCondition) || is.AccessCondition[i].(*expression.ScalarFunction).FuncName.L != ast.EQ {
 				matchProperty = false
 				break
 			}
@@ -818,34 +824,35 @@ func (p *DataSource) convertToTableScan(prop *requiredProp) (task task, err erro
 	}.init(p.allocator, p.ctx)
 	ts.SetSchema(p.schema)
 	sc := p.ctx.GetSessionVars().StmtCtx
+	ts.Ranges = ranger.FullIntRange()
+	var pkCol *expression.Column
+	if ts.Table.PKIsHandle {
+		if pkColInfo := ts.Table.GetPkColInfo(); pkColInfo != nil {
+			pkCol = expression.ColInfo2Col(ts.schema.Columns, pkColInfo)
+		}
+	}
 	if len(p.pushedDownConds) > 0 {
 		conds := make([]expression.Expression, 0, len(p.pushedDownConds))
 		for _, cond := range p.pushedDownConds {
 			conds = append(conds, cond.Clone())
 		}
-		ts.AccessCondition, ts.filterCondition = ranger.DetachColumnConditions(conds, p.tableInfo.GetPkName())
-		ts.Ranges, err = ranger.BuildTableRange(ts.AccessCondition, sc)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-	} else {
-		ts.Ranges = []types.IntColumnRange{{math.MinInt64, math.MaxInt64}}
-	}
-	statsTbl := p.statisticTable
-	rowCount := float64(statsTbl.Count)
-	var pkCol *expression.Column
-	if p.tableInfo.PKIsHandle {
-		for i, colInfo := range ts.Columns {
-			if mysql.HasPriKeyFlag(colInfo.Flag) {
-				pkCol = p.Schema().Columns[i]
-				break
-			}
-		}
 		if pkCol != nil {
-			rowCount, err = statsTbl.GetRowCountByIntColumnRanges(sc, pkCol.ID, ts.Ranges)
+			var ranges []types.Range
+			ranges, ts.AccessCondition, ts.filterCondition, err = ranger.BuildRange(sc, conds, ranger.IntRangeType, []*expression.Column{pkCol}, nil)
+			ts.Ranges = ranger.Ranges2IntRanges(ranges)
 			if err != nil {
 				return nil, errors.Trace(err)
 			}
+		} else {
+			ts.filterCondition = conds
+		}
+	}
+	statsTbl := p.statisticTable
+	rowCount := float64(statsTbl.Count)
+	if pkCol != nil {
+		rowCount, err = statsTbl.GetRowCountByIntColumnRanges(sc, pkCol.ID, ts.Ranges)
+		if err != nil {
+			return nil, errors.Trace(err)
 		}
 	}
 	cost := rowCount * scanFactor