Hi Martijn, Sorry for later reply. This feature is only supported in DataStream and doesn't be supported in MATCH_RECOGNIZE because the SQL syntax of MATCH_RECOGNIZE does not contain the semantics of this feature, which requires modification of the SQL syntax. The support above MATCH_RECOGNIZE is suitable for new FLIP to discuss.
Regards, Nicholas Jiang On 2022/05/25 11:36:33 Martijn Visser wrote: > Hi Nicholas, > > Thanks for creating the FLIP, I can imagine that there will be many use > cases who can be created using this new feature. > > The FLIP doesn't mention anything with regards to SQL, could this feature > also be supported when using MATCH_RECOGNIZE? > > Best regards, > > Martijn > https://twitter.com/MartijnVisser82 > https://github.com/MartijnVisser > > > On Sat, 7 May 2022 at 11:17, Dian Fu <dian0511...@gmail.com> wrote: > > > Hi Nicholas, > > > > Thanks a lot for bringing up this discussion. If I recall it correctly, > > this feature has been requested many times by the users and is among one of > > the most requested features in CEP. So big +1 to this feature overall. > > > > Regarding the API, the name `partialWithin` sounds a little weird. Is it > > possible to find a name which is more intuitive? Other possible solutions: > > - Reuse the existing `Pattern.within` method and change its semantic to the > > maximum time interval between patterns. Currently `Pattern.within` is used > > to define the maximum time interval between the first event and the last > > event. However, the Pattern object represents only one node in a pattern > > sequence and so it doesn't make much sense to define the maximum time > > interval between the first event and the last event on the Pattern object, > > e.g. we could move it to `PatternStreamBuilder`. However, if we choose > > this option, we'd better consider how to keep backward compatibility. > > - Introduce a series of methods when appending a new pattern to the > > existing one, e.g. `Pattern.followedBy(Pattern<T, F> group, Time > > timeInterval)`. As timeInterval is a property between patterns and so it > > makes sense to define this property when appending a new pattern. However, > > the drawback is that we need to introduce a series of methods instead of > > only one method. > > > > We need also to make the semantic clear in a few corner cases, e.g. > > - What's the semantic of `A.followedBy(B).times(3).partialWithin(1 min)`? > > Doesn't it mean that all three B events should occur in 1 minute or only > > the first B event should occur in 1 minute? > > - What's the semantic of > > `A.followedBy(GroupPattern.begin("B").followedBy("C")).partialWithin(1 > > min)``? Doesn't it mean that B and C should occur after A in 1 minute? > > > > Besides, this FLIP only describes how the newly introduced API will be > > used, however, it lacks details about how you will implement it. It doesn't > > need to be very detailed, however, you should describe the basic ideas > > behind it, e.g. how will you support A.notFollowedBy(B).partialWithin(1 > > min)? It could make sure that you have considered it thoroughly and also > > makes others confident that this feature could be implemented in a clean > > way. > > > > Regards, > > Dian > > > > > > > > On Fri, May 6, 2022 at 7:32 PM yue ma <mayuefi...@gmail.com> wrote: > > > > > hi Nicholas, > > > > > > Thanks for bringing this discussion, we also think it's a useful feature. > > > Some fine-grained timeout pattern matching can be implemented in CEP > > which > > > makes Flink CEP more powerful > > > > > > Nicholas <programg...@163.com> 于2022年5月5日周四 14:28写道： > > > > > > > Hi everyone, > > > > > > > > > > > > > > > > > > > > Pattern#withIn interface in CEP defines the maximum time interval in > > > which > > > > a matching pattern has to be completed in order to be considered valid, > > > > which interval corresponds to the maximum time gap between first and > > the > > > > last event. The interval representing the maximum time gap between > > events > > > > is required to define in the scenario like purchasing good within a > > > maximum > > > > of 5 minutes after browsing. > > > > > > > > > > > > > > > > > > > > I would like to start a discussion about FLIP-228[1], in which within > > > > between events is proposed in Pattern to support the definition of the > > > > maximum time interval in which a completed partial matching pattern is > > > > considered valid, which interval represents the maximum time gap > > between > > > > events for partial matching Pattern. > > > > > > > > > > > > > > > > > > > > Hence we propose the Pattern#partialWithin interface to define the > > > maximum > > > > time interval in which a completed partial matching pattern is > > considered > > > > valid. Please take a look at the FLIP page [1] to get more details. Any > > > > feedback about the FLIP-228 would be appreciated! > > > > > > > > > > > > > > > > > > > > [1] > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-228%3A+Support+Within+between+events+in+CEP+Pattern > > > > > > > > > > > > > > > > > > > > Best regards, > > > > > > > > Nicholas Jiang > > > > > >
