[ https://issues.apache.org/jira/browse/FLINK-4937?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15690151#comment-15690151 ]
ASF GitHub Bot commented on FLINK-4937: --------------------------------------- Github user fhueske commented on the issue: https://github.com/apache/flink/pull/2792 Thanks for the quick update @sunjincheng121! PR is good to merge! :-) > Add incremental group window aggregation for streaming Table API > ---------------------------------------------------------------- > > Key: FLINK-4937 > URL: https://issues.apache.org/jira/browse/FLINK-4937 > Project: Flink > Issue Type: Sub-task > Components: Table API & SQL > Affects Versions: 1.2.0 > Reporter: Fabian Hueske > Assignee: sunjincheng > > Group-window aggregates for streaming tables are currently not done in an > incremental fashion. This means that the window collects all records and > performs the aggregation when the window is closed instead of eagerly > updating a partial aggregate for every added record. Since records are > buffered, non-incremental aggregation requires more storage space than > incremental aggregation. > The DataStream API which is used under the hood of the streaming Table API > features [incremental > aggregation|https://ci.apache.org/projects/flink/flink-docs-release-1.2/dev/windows.html#windowfunction-with-incremental-aggregation] > using a {{ReduceFunction}}. > We should add support for incremental aggregation in group-windows. > This is a follow-up task of FLINK-4691. -- This message was sent by Atlassian JIRA (v6.3.4#6332)