Files
tidb/plan/explain.go

60 lines
1.6 KiB
Go

// Copyright 2017 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
package plan
import (
"fmt"
)
func setParents4FinalPlan(plan PhysicalPlan) {
allPlans := []PhysicalPlan{plan}
planMark := map[string]bool{}
planMark[plan.ID()] = true
for pID := 0; pID < len(allPlans); pID++ {
allPlans[pID].SetParents()
switch copPlan := allPlans[pID].(type) {
case *PhysicalTableReader:
setParents4FinalPlan(copPlan.tablePlan)
case *PhysicalIndexReader:
setParents4FinalPlan(copPlan.indexPlan)
case *PhysicalIndexLookUpReader:
setParents4FinalPlan(copPlan.indexPlan)
setParents4FinalPlan(copPlan.tablePlan)
}
for _, p := range allPlans[pID].Children() {
if !planMark[p.ID()] {
allPlans = append(allPlans, p.(PhysicalPlan))
planMark[p.ID()] = true
}
}
}
allPlans = allPlans[0:1]
planMark[plan.ID()] = false
for pID := 0; pID < len(allPlans); pID++ {
for _, p := range allPlans[pID].Children() {
p.AddParent(allPlans[pID])
if planMark[p.ID()] {
planMark[p.ID()] = false
allPlans = append(allPlans, p.(PhysicalPlan))
}
}
}
}
// ExplainInfo implements PhysicalPlan interface.
func (p *Limit) ExplainInfo() string {
return fmt.Sprintf("offset:%v, count:%v", p.Offset, p.Count)
}