// 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}} }