Uploaded image for project: 'Flink'
  1. Flink
  2. FLINK-4557

Table API Stream Aggregations

    XMLWordPrintableJSON

Details

    • New Feature
    • Status: Resolved
    • Major
    • Resolution: Fixed
    • None
    • 1.4.0
    • Table SQL / API
    • None

    Description

      The Table API is a declarative API to define queries on static and streaming tables. So far, only projection, selection, and union are supported operations on streaming tables.

      This issue and the corresponding FLIP proposes to add support for different types of aggregations on top of streaming tables. In particular, we seek to support:

      Group-window aggregates, i.e., aggregates which are computed for a group of elements. A (time or row-count) window is required to bound the infinite input stream into a finite group.

      Row-window aggregates, i.e., aggregates which are computed for each row, based on a window (range) of preceding and succeeding rows.
      Each type of aggregate shall be supported on keyed/grouped or non-keyed/grouped data streams for streaming tables as well as batch tables.

      Since time-windowed aggregates will be the first operation that require the definition of time, we also need to discuss how the Table API handles time characteristics, timestamps, and watermarks.

      The FLIP can be found here:
      https://cwiki.apache.org/confluence/display/FLINK/FLIP-11%3A+Table+API+Stream+Aggregations

      Attachments

        Issue Links

          There are no Sub-Tasks for this issue.

          Activity

            People

              Unassigned Unassigned
              twalthr Timo Walther
              Votes:
              1 Vote for this issue
              Watchers:
              13 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: