JingsongLi commented on a change in pull request #8102: [FLINK-12087][table-runtime-blink] Introduce over window operators to blink batch URL: https://github.com/apache/flink/pull/8102#discussion_r272031198
########## File path: flink-table/flink-table-runtime-blink/src/main/java/org/apache/flink/table/generated/BoundComparator.java ########## @@ -0,0 +1,49 @@ +/* + * 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.generated; + +import org.apache.flink.table.dataformat.BaseRow; + +import java.io.Serializable; + +/** + * comparing boundary values. + */ +public interface BoundComparator extends Serializable { Review comment: For example, `SELECT d, e, sum(e) over (partition by d order by e desc range between 5 PRECEDING and 4 PRECEDING) FROM Table` The above SQL is ranged according to the `e` field. The previous 5 PRECEDING means that the `e` value of current Row should be greater than or equal to the `e` value of range header plus 5. So the `BoundComparator` is used to code generate this logic. ---------------------------------------------------------------- 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] With regards, Apache Git Services
