You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
64 lines
2.2 KiB
64 lines
2.2 KiB
// Copyright 2018 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 implementation
|
|
|
|
import (
|
|
"math"
|
|
|
|
plannercore "github.com/pingcap/tidb/planner/core"
|
|
"github.com/pingcap/tidb/planner/memo"
|
|
)
|
|
|
|
// SortImpl implementation of PhysicalSort.
|
|
type SortImpl struct {
|
|
baseImpl
|
|
}
|
|
|
|
// NewSortImpl creates a new sort Implementation.
|
|
func NewSortImpl(sort *plannercore.PhysicalSort) *SortImpl {
|
|
return &SortImpl{baseImpl{plan: sort}}
|
|
}
|
|
|
|
// CalcCost calculates the cost of the sort Implementation.
|
|
func (impl *SortImpl) CalcCost(outCount float64, children ...memo.Implementation) float64 {
|
|
cnt := math.Min(children[0].GetPlan().Stats().RowCount, impl.plan.GetChildReqProps(0).ExpectedCnt)
|
|
sort := impl.plan.(*plannercore.PhysicalSort)
|
|
impl.cost = sort.GetCost(cnt, children[0].GetPlan().Schema()) + children[0].GetCost()
|
|
return impl.cost
|
|
}
|
|
|
|
// AttachChildren implements Implementation AttachChildren interface.
|
|
func (impl *SortImpl) AttachChildren(children ...memo.Implementation) memo.Implementation {
|
|
sort := impl.plan.(*plannercore.PhysicalSort)
|
|
sort.SetChildren(children[0].GetPlan())
|
|
// When the Sort orderByItems contain ScalarFunction, we need
|
|
// to inject two Projections below and above the Sort.
|
|
impl.plan = plannercore.InjectProjBelowSort(sort, sort.ByItems)
|
|
return impl
|
|
}
|
|
|
|
// NominalSortImpl is the implementation of NominalSort.
|
|
type NominalSortImpl struct {
|
|
baseImpl
|
|
}
|
|
|
|
// AttachChildren implements Implementation AttachChildren interface.
|
|
func (impl *NominalSortImpl) AttachChildren(children ...memo.Implementation) memo.Implementation {
|
|
return children[0]
|
|
}
|
|
|
|
// NewNominalSortImpl creates a new NominalSort Implementation.
|
|
func NewNominalSortImpl(sort *plannercore.NominalSort) *NominalSortImpl {
|
|
return &NominalSortImpl{baseImpl{plan: sort}}
|
|
}
|
|
|