/
optimizer.go
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/
optimizer.go
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// Copyright (c) 2013 Couchbase, 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, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
// either express or implied. See the License for the specific language governing permissions
// and limitations under the License.
package main
import (
"log"
"github.com/couchbaselabs/tuqqedin/plan"
)
type Optimizer interface {
ChooseOptimalPlan([]plan.Operator) plan.Operator
}
type CouchbaseOptimizer struct {
}
func NewCouchbaseOptimizer() *CouchbaseOptimizer {
return &CouchbaseOptimizer{}
}
func (this *CouchbaseOptimizer) ChooseOptimalPlan(plans []plan.Operator) plan.Operator {
cheapest := plans[0]
for i, plan := range plans {
planCost := plan.TotalCost()
log.Printf("Plan %d has cost: %v", i, planCost)
if planCost < cheapest.TotalCost() {
cheapest = plan
}
}
return cheapest
}