sunjincheng created FLINK-6145:
----------------------------------
Summary: Add [non-partitioned] event time OVER ROWS BETWEEN x
PRECEDING aggregation to SQL
Key: FLINK-6145
URL: https://issues.apache.org/jira/browse/FLINK-6145
Project: Flink
Issue Type: Sub-task
Components: Table API & SQL
Reporter: sunjincheng
Assignee: sunjincheng
The goal of this issue is to add support for OVER ROWS aggregations on event
time streams to the SQL interface.
Queries similar to the following should be supported:
{code}
SELECT
a,
SUM(b) OVER (ORDER BY rowTime() ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) AS
sumB,
MIN(b) OVER (ORDER BY rowTime() ROWS BETWEEN 2 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 ORDER BY clause may only have rowTime() as parameter. rowTime() is a
parameterless scalar function that just indicates event time mode.
- UNBOUNDED PRECEDING is not supported (see FLINK-5804)
- 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
(v6.3.15#6346)
