// 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 memo import ( plannercore "github.com/pingcap/tidb/planner/core" ) // Implementation defines the interface for cost of physical plan. type Implementation interface { CalcCost(outCount float64, children ...Implementation) float64 SetCost(cost float64) GetCost() float64 GetPlan() plannercore.PhysicalPlan // AttachChildren is used to attach children implementations and returns it self. AttachChildren(children ...Implementation) Implementation // GetCostLimit gets the costLimit for implementing the next childGroup. GetCostLimit(costLimit float64, children ...Implementation) float64 }