rdblue commented on code in PR #13445: URL: https://github.com/apache/iceberg/pull/13445#discussion_r2271603731
########## core/src/main/java/org/apache/iceberg/types/PruneUnknownTypes.java: ########## @@ -0,0 +1,137 @@ +/* + * 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.types; + +import java.util.List; +import java.util.stream.IntStream; +import org.apache.hadoop.util.Lists; +import org.apache.iceberg.Schema; + +/** This is used to remove UnknownTypes that should not be persistent in files */ +public class PruneUnknownTypes extends TypeUtil.SchemaVisitor<Type> { + private static final PruneUnknownTypes INSTANCE = new PruneUnknownTypes(); + + /** + * Prunes any UnknownType from a Schema + * + * @param schema a Schema + */ + public static Schema convert(Schema schema) { + Types.StructType struct = (Types.StructType) TypeUtil.visit(schema, INSTANCE); + return new Schema(struct.fields(), schema.identifierFieldIds()); + } + + /** + * Visits a schema and removes the UnknownTypes. + * + * <p>Used when creating a write schema, and skip over the UnknownTypes, since they are not + * materialized in the data files Review Comment: Not materialized in Parquet data files, but [can be converted to `NULL` in Avro](https://github.com/apache/iceberg/blob/main/format/spec.md#appendix-a-format-specific-requirements), which solves some of the problems there. -- 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
