| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.lens.cube.query.cost; |
| |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.apache.lens.cube.metadata.FactPartition; |
| import org.apache.lens.cube.metadata.UpdatePeriod; |
| import org.apache.lens.server.api.driver.LensDriver; |
| import org.apache.lens.server.api.error.LensException; |
| import org.apache.lens.server.api.query.AbstractQueryContext; |
| import org.apache.lens.server.api.query.cost.FactPartitionBasedQueryCost; |
| import org.apache.lens.server.api.query.cost.QueryCost; |
| import org.apache.lens.server.api.query.cost.QueryCostCalculator; |
| |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.Maps; |
| |
| public class FactPartitionBasedQueryCostCalculator implements QueryCostCalculator { |
| |
| public static final String UPDATE_PERIOD_WEIGHT_PREFIX = "update.period.weight."; |
| |
| /** |
| * Calculates total cost based on weights of selected tables and their selected partitions |
| * |
| * @param queryContext |
| * @param driver |
| * @return Query Cost |
| * @throws LensException |
| */ |
| |
| @SuppressWarnings("unchecked") // required for (Set<FactPartition>) casting |
| private Double getTotalPartitionCost(final AbstractQueryContext queryContext, LensDriver driver) |
| throws LensException { |
| if (queryContext.getDriverRewriterPlan(driver) == null) { |
| return null; |
| } |
| double cost = 0; |
| for (Map.Entry<String, Set<?>> entry : getAllPartitions(queryContext, driver).entrySet()) { |
| // Have to do instanceof check, since it can't be handled by polymorphism. |
| // The '?' is either a FactPartition or a String. When we decide to write a |
| // DimtablePartition, we can probably think about using polymorphism. |
| if (!entry.getValue().isEmpty() && entry.getValue().iterator().next() instanceof FactPartition) { |
| Set<FactPartition> factParts = (Set<FactPartition>) entry.getValue(); |
| for (FactPartition partition : factParts) { |
| double allTableWeights = |
| partition.getAllTableWeights(ImmutableMap.copyOf(queryContext.getTableWeights(driver))); |
| if (allTableWeights == 0) { |
| allTableWeights = 1; |
| } |
| cost += allTableWeights * getNormalizedUpdatePeriodCost(partition.getPeriod(), driver); |
| } |
| } else { |
| // increase cost for every dimtable partition |
| cost += 1.0; |
| } |
| } |
| return cost; |
| } |
| |
| /** |
| * Normalized cost of an update period. update period weight multiplied by number of partitions of that update period. |
| * |
| * @param updatePeriod |
| * @param driver |
| * @return normalized cost. |
| * @throws LensException |
| */ |
| private double getNormalizedUpdatePeriodCost(final UpdatePeriod updatePeriod, LensDriver driver) |
| throws LensException { |
| double weight = driver.getConf().getDouble(UPDATE_PERIOD_WEIGHT_PREFIX + updatePeriod.name().toLowerCase(), |
| updatePeriod.getNormalizationFactor()); |
| return weight * updatePeriod.weight() / UpdatePeriod.DAILY.weight(); |
| } |
| |
| @Override |
| public QueryCost calculateCost(final AbstractQueryContext queryContext, LensDriver driver) throws LensException { |
| Double cost = getTotalPartitionCost(queryContext, driver); |
| return cost == null ? null : new FactPartitionBasedQueryCost(cost); |
| } |
| |
| public Map<String, Set<?>> getAllPartitions(AbstractQueryContext queryContext, LensDriver driver) { |
| if (queryContext.getDriverRewriterPlan(driver) != null) { |
| return queryContext.getDriverRewriterPlan(driver).getPartitions(); |
| } |
| return Maps.newHashMap(); |
| } |
| } |