[
https://issues.apache.org/jira/browse/FLINK-8144?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16267921#comment-16267921
]
ASF GitHub Bot commented on FLINK-8144:
---------------------------------------
Github user dianfu commented on the issue:
https://github.com/apache/flink/pull/5063
@fhueske Thanks a lot for your comments. Definitely agree with you on the
motivation of punctuated watermark. But in practice, there are many cases there
is no watermark information in the source data at all. So we have to generate
one watermark for every incoming event.
> Optimize the timer logic in RowTimeUnboundedOver
> ------------------------------------------------
>
> Key: FLINK-8144
> URL: https://issues.apache.org/jira/browse/FLINK-8144
> Project: Flink
> Issue Type: Bug
> Components: Table API & SQL
> Reporter: Dian Fu
> Assignee: Dian Fu
> Fix For: 1.5.0
>
>
> Currently the logic of {{RowTimeUnboundedOver}} is as follows:
> 1) When element comes, buffer it in MapState and and register a timer at
> {{current watermark + 1}}
> 2) When event timer triggered, scan the MapState and find the elements below
> the current watermark and process it. If there are remaining elements to
> process, register a new timer at {{current watermark + 1}}.
> Let's assume that watermark comes about 5 seconds later than the event on
> average, then we will scan about 5000 times the MapState before actually
> processing the events.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
