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Haohui Mai commented on FLINK-5655: ----------------------------------- I'm particularly interested in the part that compiles the sliding windows from Calcite down to the DataStream operators. Maybe a dumb question -- I wonder, is it possible to specify sliding grouped windows introduced in FLINK-4691 in this syntax? Essentially I am looking at something that directly maps to the sliding windows in the {{DataStream}} / {{Table}} APIs. Essentially I'm looking for https://ci.apache.org/projects/flink/flink-docs-release-1.2/dev/windows.html#sliding-windows. I can see there are two possible ways to express the sliding windows: {noformat} 1. SELECT SUM(b) OVER(PARTITION BY SlidingWindowGap(...) RANGE BETWEEN INTERVAL '1' HOUR PRECEDING AND CURRENT ROW)) FROM table 2. SELECT SUM(b) FROM table GROUP BY SlidingWindow(size, interval) {noformat} The approach (2) is implemented by https://msdn.microsoft.com/en-us/library/azure/dn835051.aspx. My question is that are (1) and (2) semantically equivalent? What is the right way to express grouped sliding windows? > Add event time OVER RANGE BETWEEN x PRECEDING aggregation to SQL > ---------------------------------------------------------------- > > Key: FLINK-5655 > URL: https://issues.apache.org/jira/browse/FLINK-5655 > Project: Flink > Issue Type: Sub-task > Components: Table API & SQL > Reporter: Fabian Hueske > Assignee: Shaoxuan Wang > > The goal of this issue is to add support for OVER RANGE aggregations on event > 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 rowTime() RANGE BETWEEN INTERVAL '1' > HOUR PRECEDING AND CURRENT ROW) AS sumB, > MIN(b) OVER (PARTITION BY c ORDER BY rowTime() RANGE BETWEEN INTERVAL '1' > HOUR 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 rowTime() as parameter. rowTime() is a > parameterless scalar function that just indicates processing time mode. > - UNBOUNDED PRECEDING is not supported (see FLINK-5658) > - 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)