snuyanzin commented on code in PR #25707: URL: https://github.com/apache/flink/pull/25707#discussion_r1861853852
########## flink-table/flink-table-common/src/main/java/org/apache/flink/table/annotation/StateHint.java: ########## @@ -0,0 +1,73 @@ +/* + * 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.annotation; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.table.functions.AggregateFunction; +import org.apache.flink.table.functions.ProcessTableFunction; +import org.apache.flink.table.functions.TableAggregateFunction; + +import java.lang.annotation.ElementType; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; +import java.lang.annotation.Target; + +/** + * A hint that declares an intermediate result (i.e. state entry) that is managed by the framework + * (i.e. Flink managed state). + * + * <p>State hints are primarily intended for {@link ProcessTableFunction}. A PTF supports multiple + * state entries at the beginning of an eval()/onTimer() method (after an optional context + * parameter). + * + * <p>Aggregating functions (i.e. {@link AggregateFunction} and {@link TableAggregateFunction}) + * support a single state entry at the beginning of an accumulate()/retract() method (i.e. the + * accumulator). + * + * <p>For example, {@code @StateHint(name = "count", type = @DataTypeHint("BIGINT"))} is a state + * entry with the data type BIGINT named "count". + * + * <p>Note: Usually, a state entry is partitioned by a key and can not be accessed globally. The + * partitioning (or whether it is only a single partition) is defined by the corresponding function + * call. + * + * @see FunctionHint + */ +@PublicEvolving +@Retention(RetentionPolicy.RUNTIME) +@Target({ElementType.TYPE, ElementType.METHOD, ElementType.PARAMETER}) +public @interface StateHint { Review Comment: Also a question: whether it should be covered in doc as well? -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
