RussellSpitzer commented on a change in pull request #2609: URL: https://github.com/apache/iceberg/pull/2609#discussion_r669917070
########## File path: core/src/main/java/org/apache/iceberg/actions/SortStrategy.java ########## @@ -0,0 +1,124 @@ +/* + * 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.iceberg.actions; + +import java.util.Map; +import java.util.Set; +import org.apache.iceberg.FileScanTask; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableSet; +import org.apache.iceberg.util.PropertyUtil; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * A rewrite strategy for data files which aims to reorder data with data files to optimally lay them out + * in relation to a column. For example, if the Sort strategy is used on a set of files which is ordered + * by column x and original has files File A (x: 0 - 50), File B ( x: 10 - 40) and File C ( x: 30 - 60), + * this Strategy will attempt to rewrite those files into File A' (x: 0-20), File B' (x: 21 - 40), + * File C' (x: 41 - 60). + * <p> + * Currently the there is no clustering detection and we will rewrite all files if {@link SortStrategy#REWRITE_ALL} Review comment: This clustering is within a partition, perhaps the naming is not great here but I"m talking about whether we have several datafiles which cover the same region of the sort column. Like hopefully in the future we can detect files A, B, C have significant overlap so we should rewrite those 3 files. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
