[
https://issues.apache.org/jira/browse/FLINK-7169?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16119857#comment-16119857
]
ASF GitHub Bot commented on FLINK-7169:
---------------------------------------
Github user dawidwys commented on a diff in the pull request:
https://github.com/apache/flink/pull/4331#discussion_r132166483
--- Diff:
flink-libraries/flink-cep/src/main/java/org/apache/flink/cep/nfa/NFA.java ---
@@ -157,15 +157,28 @@
*/
private boolean nfaChanged;
+ /**
+ * Store the skip strategy.
+ */
+ private AfterMatchSkipStrategy afterMatchSkipStrategy;
--- End diff --
I would not add it to NFA. I think it is a static data, that should not be
serialized each time with `NFA`. We already have problems to remove `State`s,
`Condition`s and `handleTimeout` from serializing within `NFA`. It also makes
maintaining serializing compatbility hard. How about adding it to the
`NFAFactory` and passing it to `NFA#process`(It is the only place where it is
needed).
I know it will require passing it in multiple places e.g.
`KeyedCEPPatternOperator` and 'TimeoutKeyedCEPPatternOperator` but it will be
easier after #4320.
> 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.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
