flink-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Fabian Hueske (JIRA)" <j...@apache.org>
Subject [jira] [Created] (FLINK-5656) Add processing time OVER ROWS BETWEEN UNBOUNDED PRECEDING aggregation to SQL
Date Thu, 26 Jan 2017 13:49:24 GMT
Fabian Hueske created FLINK-5656:
------------------------------------

             Summary: Add processing time OVER ROWS BETWEEN UNBOUNDED PRECEDING aggregation
to SQL
                 Key: FLINK-5656
                 URL: https://issues.apache.org/jira/browse/FLINK-5656
             Project: Flink
          Issue Type: Sub-task
          Components: Table API & SQL
            Reporter: Fabian Hueske


The goal of this issue is to add support for OVER ROW aggregations on processing time streams
to the SQL interface.

Queries similar to the following should be supported:
{code}
SELECT 
  a, 
  SUM(b) OVER (PARTITION BY c ORDER BY procTime() ROW BETWEEN UNBOUNDED PRECEDING AND CURRENT
ROW) AS sumB,
  MIN(b) OVER (PARTITION BY c ORDER BY procTime() ROW BETWEEN UNBOUNDED PRECEDING AND CURRENT
ROW) AS minB
FROM myStream
{code}

The following restrictions should initially apply:
- All OVER clauses in the same SELECT clause must be exactly the same.
- The PARTITION BY clause is optional (no partitioning results in single threaded execution).
- The ORDER BY clause may only have procTime() as parameter. procTime() is a parameterless
scalar function that just indicates processing time mode.
- x PRECEDING is not supported (see FLINK-5653)
- FOLLOWING is not supported.

The restrictions will be resolved in follow up issues. If we find that some of the restrictions
are trivial to address, we can add the functionality in this issue as well.

This issue includes:
- Design of the DataStream operator to compute OVER ROW aggregates
- Translation from Calcite's RelNode representation (LogicalProject with RexOver expression).




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message