rdblue commented on a change in pull request #1495: URL: https://github.com/apache/iceberg/pull/1495#discussion_r497098779
########## File path: mr/src/main/java/org/apache/iceberg/mr/hive/HiveIcebergMetaHook.java ########## @@ -0,0 +1,161 @@ +/* + * 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.mr.hive; + +import java.util.HashSet; +import java.util.Properties; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.Stream; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.hive.metastore.HiveMetaHook; +import org.apache.hadoop.hive.metastore.api.MetaException; +import org.apache.iceberg.BaseMetastoreTableOperations; +import org.apache.iceberg.PartitionSpecParser; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SchemaParser; +import org.apache.iceberg.Table; +import org.apache.iceberg.exceptions.NoSuchTableException; +import org.apache.iceberg.hive.HiveTableOperations; +import org.apache.iceberg.mr.Catalogs; +import org.apache.iceberg.mr.InputFormatConfig; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class HiveIcebergMetaHook implements HiveMetaHook { + private static final Logger LOG = LoggerFactory.getLogger(HiveIcebergMetaHook.class); + private static final Set<String> PARAMETERS_TO_REMOVE = Stream + .of(InputFormatConfig.TABLE_SCHEMA, InputFormatConfig.PARTITION_SPEC, Catalogs.LOCATION, Catalogs.NAME) + .collect(Collectors.toCollection(HashSet::new)); + private static final Set<String> PROPERTIES_TO_REMOVE = Stream + .of(InputFormatConfig.HIVE_DELETE_BACKING_TABLE, "storage_handler", "EXTERNAL") + .collect(Collectors.toCollection(HashSet::new)); + + private final Configuration conf; + private Table icebergTable = null; + private Properties catalogProperties; + private boolean deleteIcebergTable; + + public HiveIcebergMetaHook(Configuration conf) { + this.conf = conf; + } + + @Override + public void preCreateTable(org.apache.hadoop.hive.metastore.api.Table hmsTable) { + catalogProperties = getCatalogProperties(hmsTable); + try { + icebergTable = Catalogs.loadTable(conf, catalogProperties); + + Preconditions.checkArgument(catalogProperties.getProperty(InputFormatConfig.TABLE_SCHEMA) == null, + "Iceberg table already created - can not use provided schema"); + Preconditions.checkArgument(catalogProperties.getProperty(InputFormatConfig.PARTITION_SPEC) == null, + "Iceberg table already created - can not use provided partition specification"); + + LOG.info("Iceberg table already exists {}", icebergTable); + } catch (NoSuchTableException nte) { + String schemaString = catalogProperties.getProperty(InputFormatConfig.TABLE_SCHEMA); + Preconditions.checkNotNull(schemaString, "Please provide a table schema"); + // Just check if it is parsable, and later use for partition specification parsing + Schema schema = SchemaParser.fromJson(schemaString); + + String specString = catalogProperties.getProperty(InputFormatConfig.PARTITION_SPEC); + if (specString != null) { + // Just check if it is parsable + PartitionSpecParser.fromJson(schema, schemaString); + } + + // Allow purging table data if the table is created now and not set otherwise + if (hmsTable.getParameters().get(InputFormatConfig.HIVE_DELETE_BACKING_TABLE) == null) { + hmsTable.getParameters().put(InputFormatConfig.HIVE_DELETE_BACKING_TABLE, "TRUE"); Review comment: > managed means that it is hive-owned and in hive acid layout Thanks! I didn't realize that managed now means that it uses the Hive ACID layout. I agree that if we can reuse a property, then we should. I like the idea to use `external.table.purge`. I would set that automatically when creating a table from Hive, but I don't think it makes sense to drop the table data automatically based on using `HiveCatalog`. Leaving metadata in place to be cleaned up by something like `RemoveOrphanFilesAction` is nice so that you can un-delete tables when a user dropped one accidentally. For example, we've seen lots of cases where tables in the wrong db are dropped because the user thought they had run `USE`. I'd say let's keep it simple and just use the existing Hive property. ---------------------------------------------------------------- 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. 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