dawidwys commented on a change in pull request #8214: [FLINK-11476] [table] Create CatalogManager to manage multiple catalogs and encapsulate Calcite schema URL: https://github.com/apache/flink/pull/8214#discussion_r280532280
########## File path: flink-table/flink-table-planner-blink/src/main/java/org/apache/flink/table/catalog/FlinkCatalogManager.java ########## @@ -0,0 +1,124 @@ +/* + * 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.flink.table.catalog; + +import org.apache.flink.table.api.CatalogAlreadyExistsException; +import org.apache.flink.table.api.CatalogNotExistException; +import org.apache.flink.util.StringUtils; + +import org.apache.calcite.jdbc.CalciteSchema; +import org.apache.calcite.schema.SchemaPlus; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.HashMap; +import java.util.Map; +import java.util.Set; + +import static org.apache.flink.util.Preconditions.checkArgument; +import static org.apache.flink.util.Preconditions.checkNotNull; + +/** + * A CatalogManager implementation for Flink. + * TODO: [FLINK-11275] Decouple CatalogManager with Calcite + * Idealy FlinkCatalogManager should be in flink-table-api-java module. + * But due to that it currently depends on Calcite, a dependency that flink-table-api-java doesn't have right now. + * We temporarily put FlinkCatalogManager in flink-table-planner-blink. + */ +public class FlinkCatalogManager implements CatalogManager { + private static final Logger LOG = LoggerFactory.getLogger(FlinkCatalogManager.class); + + public static final String BUILTIN_CATALOG_NAME = "builtin"; + + // The catalog to hold all registered and translated tables + // We disable caching here to prevent side effects + private CalciteSchema internalSchema = CalciteSchema.createRootSchema(false, false); + private SchemaPlus rootSchema = internalSchema.plus(); + + // A map between names and catalogs. + private Map<String, ReadableCatalog> catalogs; + + // The name of the default catalog and schema + private String currentCatalogName; + + public FlinkCatalogManager() { + LOG.info("Initializing FlinkCatalogManager"); + catalogs = new HashMap<>(); + + GenericInMemoryCatalog inMemoryCatalog = new GenericInMemoryCatalog(BUILTIN_CATALOG_NAME); Review comment: I agree that there might be implementations that for time being do not support writing and might throw exception. In general I think though all the implementation do support writing in a way. I agree e.g. the owner of a platform might decide to disallow writing, but this should be rather done with some sort of access roles or property base etc. In the end all catalogs do support writing, otherwise there would be no way to enter data into them. The method you mentioned `registerTable` is part of the `ReadableWritableCatalog` not `ReadableCatalog`, if the `CatalogManager` works only with `ReadableCatalog`, we would have to perform instance checks and hard casts all the time. I see no reason for that. I believe we can just have a single `Catalog` interface that might throw exception if it should not be modified or just expose a flag such as `isMutable`. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
