rdblue commented on a change in pull request #1870: URL: https://github.com/apache/iceberg/pull/1870#discussion_r547560663
########## File path: core/src/main/java/org/apache/iceberg/jdbc/JdbcNamespace.java ########## @@ -0,0 +1,169 @@ +/* + * 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.jdbc; + +import com.fasterxml.jackson.core.JsonProcessingException; +import java.sql.Connection; +import java.sql.PreparedStatement; +import java.sql.ResultSet; +import java.sql.SQLException; +import java.util.Arrays; +import java.util.List; +import java.util.Map; +import java.util.stream.Stream; +import org.apache.iceberg.catalog.Namespace; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class JdbcNamespace { Review comment: This adds quite a bit of complexity to the JDBC implementation because it requires a separate table for namespace and stores both namespace name and metadata as JSON objects. I think that ensuring consistency between the two tables adds a lot of unnecessary complexity. What happens if a table is added to a namespace that as it is concurrently deleted? I think a much simpler implementation is to omit the namespace table and determine whether a namespace exists based on whether there are any tables in it. As long as we can guarantee atomic changes to the tables table, consistency problems go away. That's also a simpler way to start a JDBC implementation. Then we can add namespace metadata later in a way that doesn't have those problems. @ismailsimsek what do you think about removing this and implementing `namespaceExists` based just on the tables table? ---------------------------------------------------------------- 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]
