luoyuxia commented on code in PR #21658: URL: https://github.com/apache/flink/pull/21658#discussion_r1070509789
########## flink-table/flink-table-common/src/main/java/org/apache/flink/table/connector/sink/abilities/SupportsDeletePushDown.java: ########## @@ -0,0 +1,82 @@ +/* + * 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.connector.sink.abilities; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.table.connector.sink.DynamicTableSink; +import org.apache.flink.table.expressions.ResolvedExpression; + +import java.util.List; +import java.util.Optional; + +/** + * Enable to delete existing data in a {@link DynamicTableSink} directly according to the filter + * expressions in {@code DELETE} clause. + * + * <p>Given the following SQL: + * + * <pre>{@code + * DELETE FROM t WHERE (a = '1' OR a = '2') AND b IS NOT NULL; + * + * }</pre> + * + * <p>In the example above, {@code [a = '1' OR a = '2']} and {@code [b IS NOT NULL]} are acceptable + * filters. + * + * <p>Flink will get the filters in conjunctive form and push down the filters into sink by calling + * method {@link #applyDeleteFilters} in the planner phase. If it returns true, Flink will then call + * method to execute the actual delete in execution phase. + * + * <p>Note: in the case that the filter expression is not available, e.g., sub-query or {@link + * #applyDeleteFilters} returns false, if the sink implements {@link SupportsRowLevelDelete}, Flink + * will try to rewrite the delete operation and produce row-level changes, see {@link + * SupportsRowLevelDelete} for more details. Otherwise, Flink will throw {@link + * UnsupportedOperationException}. + */ Review Comment: Thanks for the advice. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
