/* This file is part of VoltDB.
* Copyright (C) 2008-2017 VoltDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with VoltDB. If not, see <http://www.gnu.org/licenses/>.
*/
package org.voltdb.planner;
import java.util.HashMap;
/**
* The trivial cost model returns one for any plan. In theory this will
* always select the first plan given to it, but it doesn't really matter.
*
*/
public class TrivialCostModel extends AbstractCostModel {
@Override
public double getPlanCost(PlanStatistics stats) {
double cost = 0;
// just add up the total tuples read for the plan
for (int i = 0; i < stats.getLevelCount(); i++) {
HashMap<StatsField, Long> level = stats.getStatisticsForLevel(i);
Long levelValueObj = level.get(StatsField.TUPLES_READ);
long levelValue = (levelValueObj == null) ? 0 : levelValueObj.longValue();
cost += levelValue;
}
return cost;
}
}