jzhuge commented on code in PR #37556: URL: https://github.com/apache/spark/pull/37556#discussion_r1014530432
########## sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/ViewCatalog.java: ########## @@ -0,0 +1,155 @@ +/* + * 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.spark.sql.connector.catalog; + +import java.util.Map; + +import org.apache.spark.annotation.DeveloperApi; +import org.apache.spark.sql.catalyst.analysis.NoSuchNamespaceException; +import org.apache.spark.sql.catalyst.analysis.NoSuchViewException; +import org.apache.spark.sql.catalyst.analysis.ViewAlreadyExistsException; +import org.apache.spark.sql.types.StructType; + +/** + * Catalog methods for working with views. + */ +@DeveloperApi +public interface ViewCatalog extends CatalogPlugin { + + /** + * List the views in a namespace from the catalog. + * <p> + * If the catalog supports tables, this must return identifiers for only views and not tables. + * + * @param namespace a multi-part namespace + * @return an array of Identifiers for views + * @throws NoSuchNamespaceException If the namespace does not exist (optional). + */ + Identifier[] listViews(String... namespace) throws NoSuchNamespaceException; + + /** + * Load view metadata by {@link Identifier ident} from the catalog. + * <p> + * If the catalog supports tables and contains a table for the identifier and not a view, + * this must throw {@link NoSuchViewException}. + * + * @param ident a view identifier + * @return the view description + * @throws NoSuchViewException If the view doesn't exist or is a table + */ + View loadView(Identifier ident) throws NoSuchViewException; + + /** + * Invalidate cached view metadata for an {@link Identifier identifier}. + * <p> + * If the view is already loaded or cached, drop cached data. If the view does not exist or is + * not cached, do nothing. Calling this method should not query remote services. + * + * @param ident a view identifier + */ + default void invalidateView(Identifier ident) { + } + + /** + * Test whether a view exists using an {@link Identifier identifier} from the catalog. + * <p> + * If the catalog supports views and contains a view for the identifier and not a table, + * this must return false. + * + * @param ident a view identifier + * @return true if the view exists, false otherwise + */ + default boolean viewExists(Identifier ident) { + try { + return loadView(ident) != null; + } catch (NoSuchViewException e) { + return false; + } + } + + /** + * Create a view in the catalog. + * + * @param ident a view identifier + * @param sql the SQL text that defines the view + * @param currentCatalog the current catalog + * @param currentNamespace the current namespace + * @param schema the view query output schema + * @param columnAliases the column aliases + * @param columnComments the column comments + * @param properties the view properties + * @return the view created + * @throws ViewAlreadyExistsException If a view or table already exists for the identifier + * @throws NoSuchNamespaceException If the identifier namespace does not exist (optional) + */ + View createView( + Identifier ident, + String sql, + String currentCatalog, + String[] currentNamespace, + StructType schema, + String[] columnAliases, Review Comment: I'd hesitate to do so because these have different meanings: one is more like "CreateViewRequest", the other like "ViewMetadata". Using the same interface may cause confusion and evolving one of them in the future. -- 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: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
