[FLINK-6392] Change the alias of Window from optional to essential.

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.0
• Fix Version/s: 1.3.0
• Component/s: Table SQL / API
• Assignee: sunjincheng
• Reporter: sunjincheng
• Created: 26/Apr/17 23:12
• Updated: 27/Apr/17 16:00
• Resolved: 27/Apr/17 16:00

Description

Currently, The window clause use case looks like as following:

tab //Table('a,'b,'c)
   .window( Slide over 10.milli every 5.milli  as 'w) 
   .groupBy('w,'a,'b) 
   .select('a, 'b, 'c.sum, 'w.start, 'w.end)

As we see the alias of window is essential. But the current implementation of the TableAPI does not have the constraint for the alias,So we must refactoring the API definition using TYPE SYSTEM lead to constraint for the alias.

Issue Links

• links to: GitHub Pull Request #3786