EmmyMiao87 commented on a change in pull request #6420: URL: https://github.com/apache/incubator-doris/pull/6420#discussion_r687380762
########## File path: fe/fe-core/src/main/java/org/apache/doris/statistics/OlapTableStats.java ########## @@ -0,0 +1,46 @@ +// 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.doris.statistics; + +import com.google.common.collect.Maps; + +import java.util.Map; + +/** + * There are the statistics of OlapTable. + * The @OlapTableStats are mainly used to provide input for the Optimizer's cost model. + * + * There are three kinds of statistics of OlapTable. + * @rowCount: The row count of OlapTable. There are two ways to obtain value: + * 1. The sum row count of @TabletStats which maybe an inaccurate value. + * 2. count(*) of OlapTable which is an accurate value. + * @dataSize: The data size of OlapTable. This is an inaccurate value, + * which is obtained by summing the @dataSize of @TabletStats. + * @idToTabletStats: <@Long tabletId, @TabletStats tabletStats> + * Each tablet in the OlapTable will have corresponding @TabletStats. + * Those @TabletStats are recorded in @idToTabletStats form of MAP. + * This facilitates the optimizer to quickly find the corresponding + * @TabletStats based on the tablet id. + * At the same time, both @rowCount and @dataSize can also be obtained + * from the sum of all @TabletStats. + * + */ +public class OlapTableStats extends TableStats { + + private Map<Long, TabletStats> idToTabletStats = Maps.newHashMap(); Review comment: All classes in statistical information are currently designed to be completely decoupled from other meta-information. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org
