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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)