[
https://issues.apache.org/jira/browse/FLINK-6969?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16065057#comment-16065057
]
ASF GitHub Bot commented on FLINK-6969:
---------------------------------------
Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/4183#discussion_r124298519
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/queryConfig.scala
---
@@ -37,6 +37,14 @@ class BatchQueryConfig private[table] extends QueryConfig
class StreamQueryConfig private[table] extends QueryConfig {
/**
+ * The deferredComputationTime is a strategy config of deferred
computation that used to deal
+ * with late arriving data. For example, instead of computing a
tumbling window of 1 hour at each
+ * full hour, we can add a deferred computation interval of 15 minute
to compute the result
+ * quarter past each full hour.
+ */
+ private var deferredComputationTime: Long = 0L
--- End diff --
Should we call this parameter rather `firstResultTimeOffset`? This would
allow us to also use it to configure early results later. The value would be an
offset from the original computation time. A positive value (> 0) would mean
deferred computation (later than usual) and a negative value (<0) would mean an
early computation / early result.
> Add support for deferred computation for group window aggregates
> ----------------------------------------------------------------
>
> Key: FLINK-6969
> URL: https://issues.apache.org/jira/browse/FLINK-6969
> Project: Flink
> Issue Type: New Feature
> Components: Table API & SQL
> Reporter: Fabian Hueske
> Assignee: sunjincheng
>
> Deferred computation is a strategy to deal with late arriving data and avoid
> updates of previous results. Instead of computing a result as soon as it is
> possible (i.e., when a corresponding watermark was received), deferred
> computation adds a configurable amount of slack time in which late data is
> accepted before the result is compute. For example, instead of computing a
> tumbling window of 1 hour at each full hour, we can add a deferred
> computation interval of 15 minute to compute the result quarter past each
> full hour.
> This approach adds latency but can reduce the number of update esp. in use
> cases where the user cannot influence the generation of watermarks. It is
> also useful if the data is emitted to a system that cannot update result
> (files or Kafka). The deferred computation interval should be configured via
> the {{QueryConfig}}.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
