edgarRd commented on a change in pull request #1332: URL: https://github.com/apache/iceberg/pull/1332#discussion_r473479534
########## File path: flink/src/main/java/org/apache/iceberg/flink/TableLoader.java ########## @@ -0,0 +1,107 @@ +/* + * 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.flink; + +import java.io.Closeable; +import java.io.IOException; +import java.io.Serializable; +import org.apache.hadoop.conf.Configuration; +import org.apache.iceberg.Table; +import org.apache.iceberg.catalog.Catalog; +import org.apache.iceberg.catalog.TableIdentifier; +import org.apache.iceberg.hadoop.HadoopTables; + +/** + * Serializable loader to load an Iceberg {@link Table}. + * Flink needs to get {@link Table} objects in the cluster (for example, to get splits), not just on the client side. + * So we need an Iceberg table loader to get the {@link Table} object. + */ +public interface TableLoader extends Closeable, Serializable { + + void open(Configuration configuration); + + Table loadTable(); + + static TableLoader fromCatalog(CatalogLoader catalogLoader, TableIdentifier identifier) { + return new CatalogTableLoader(catalogLoader, identifier); + } + + static TableLoader fromHadoopTable(String location) { + return new HadoopTableLoader(location); + } + + class HadoopTableLoader implements TableLoader { Review comment: Right, I think part of the discussion is that providing a table via this API does not guarantee the atomic commit on table changes, therefore we have `HiveCatalog` for tables that are backed in systems like `s3`. While `HadoopCatalog` that does not require HMS coordination since the filesystem itself has atomic renames. I'm not sure which case specifically this specific Flink implementation will use, but as mentioned in https://github.com/apache/iceberg/issues/1306#issuecomment-671627947 it seems dangerous to provide a way to provide tables loaded with `HadoopTables` if there's no context of the underlying limitations. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
