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https://issues.apache.org/jira/browse/FLINK-7169?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16120938#comment-16120938
 ] 

ASF GitHub Bot commented on FLINK-7169:
---------------------------------------

Github user yestinchen commented on a diff in the pull request:

    https://github.com/apache/flink/pull/4331#discussion_r132349108
  
    --- Diff: 
flink-libraries/flink-cep/src/main/java/org/apache/flink/cep/nfa/AfterMatchSkipStrategy.java
 ---
    @@ -0,0 +1,276 @@
    +/*
    + * 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.cep.nfa;
    +
    +import org.apache.flink.api.common.typeutils.CompatibilityResult;
    +import org.apache.flink.api.common.typeutils.CompatibilityUtil;
    +import 
org.apache.flink.api.common.typeutils.CompositeTypeSerializerConfigSnapshot;
    +import org.apache.flink.api.common.typeutils.TypeDeserializerAdapter;
    +import org.apache.flink.api.common.typeutils.TypeSerializer;
    +import org.apache.flink.api.common.typeutils.TypeSerializerConfigSnapshot;
    +import org.apache.flink.api.common.typeutils.UnloadableDummyTypeSerializer;
    +import org.apache.flink.api.java.tuple.Tuple2;
    +import org.apache.flink.core.memory.DataInputView;
    +import org.apache.flink.core.memory.DataInputViewStreamWrapper;
    +import org.apache.flink.core.memory.DataOutputView;
    +import org.apache.flink.core.memory.DataOutputViewStreamWrapper;
    +
    +import java.io.ByteArrayInputStream;
    +import java.io.ByteArrayOutputStream;
    +import java.io.IOException;
    +import java.io.ObjectInputStream;
    +import java.io.ObjectOutputStream;
    +import java.io.Serializable;
    +import java.util.List;
    +
    +
    +/**
    + * Indicate the skip strategy after a match process.
    + * <p>There're four kinds of strategies:
    + * SKIP_PAST_LAST_EVENT,
    + * SKIP_TO_NEXT_EVENT,
    + * SKIP_TO_FIRST_<code>PATTERN</code> and
    + * SKIP_TO_LAST_<code>PATTERN</code>
    + * </p>
    + */
    +public class AfterMatchSkipStrategy implements Serializable {
    +
    +   // default strategy
    +   SkipStrategy strategy = SkipStrategy.SKIP_TO_NEXT_EVENT;
    +
    +   // fields
    +   String patternName = null;
    +
    +   public AfterMatchSkipStrategy(){
    +           this(SkipStrategy.SKIP_TO_NEXT_EVENT, null);
    +   }
    +
    +   public AfterMatchSkipStrategy(SkipStrategy strategy) {
    +           this(strategy, null);
    +   }
    +
    +   public AfterMatchSkipStrategy(SkipStrategy strategy, String 
patternName) {
    --- End diff --
    
    Good idea, I like that.


> Support AFTER MATCH SKIP function in CEP library API
> ----------------------------------------------------
>
>                 Key: FLINK-7169
>                 URL: https://issues.apache.org/jira/browse/FLINK-7169
>             Project: Flink
>          Issue Type: Sub-task
>          Components: CEP
>            Reporter: Yueting Chen
>            Assignee: Yueting Chen
>             Fix For: 1.4.0
>
>
> In order to support Oracle's MATCH_RECOGNIZE on top of the CEP library, we 
> need to support AFTER MATCH SKIP function in CEP API.
> There're four options in AFTER MATCH SKIP, listed as follows:
> 1. AFTER MATCH SKIP TO NEXT ROW: resume pattern matching at the row after the 
> first row of the current match.
> 2. AFTER MATCH SKIP PAST LAST ROW: resume pattern matching at the next row 
> after the last row of the current match.
> 3. AFTER MATCH SKIP TO FIST *RPV*: resume pattern matching at the first row 
> that is mapped to the row pattern variable RPV.
> 4. AFTER MATCH SKIP TO LAST *RPV*: resume pattern matching at the last row 
> that is mapped to the row pattern variable RPV.
> I think we can introduce a new function to `CEP` class, which takes a new 
> parameter as AfterMatchSKipStrategy.
> The new API may looks like this
> {code}
> public static <T> PatternStream<T> pattern(DataStream<T> input, Pattern<T, ?> 
> pattern, AfterMatchSkipStrategy afterMatchSkipStrategy) 
> {code}
> We can also make `SKIP TO NEXT ROW` as the default option, because that's 
> what CEP library behaves currently.



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