flyrain commented on code in PR #6344: URL: https://github.com/apache/iceberg/pull/6344#discussion_r1055938410
########## spark/v3.3/spark/src/main/java/org/apache/iceberg/spark/ChangelogIterator.java: ########## @@ -0,0 +1,204 @@ +/* + * 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.spark; + +import java.io.Serializable; +import java.util.Iterator; +import java.util.List; +import java.util.Objects; +import org.apache.iceberg.ChangelogOperation; +import org.apache.iceberg.relocated.com.google.common.collect.Iterators; +import org.apache.spark.sql.Row; +import org.apache.spark.sql.RowFactory; +import org.apache.spark.sql.catalyst.expressions.GenericInternalRow; +import org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema; + +/** + * An iterator that transforms rows from changelog tables within a single Spark task. It assumes + * that rows are sorted by identifier columns and change type. + * + * <p>It removes the carry-over rows. Carry-over rows are the result of a removal and insertion of + * the same row within an operation because of the copy-on-write mechanism. For example, given a + * file which contains row1 (id=1, data='a') and row2 (id=2, data='b'). A copy-on-write delete of + * row2 would require erasing this file and preserving row1 in a new file written with row1' which Review Comment: Good points. Changed to actual value. -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
