[
https://issues.apache.org/jira/browse/DERBY-2998?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12551241
]
Thomas Nielsen commented on DERBY-2998:
---------------------------------------
Dan,
Yes, this is still a work in progress and a lot of the comments reflect this. I
dove off the deep end to get my feet wet with derby, and I'm still trying to
learn how to swim :)
That linked wikipage is, or at least was intended to be, the writeup of what
this issue should end as.
The future goal is for derby to support window functions over both named and
unnamed windows, but that needs to be done in multiple jiras IMHO as it's a
large task. This jira will only implement the ROW_NUMBER() function, and not
the window specification (OVER <window name or specification>). As long as the
window specification remains unsupported, the syntax will be deviating from the
standard. It's not about introducing non-standard expressions, but a step
towards having standard window functions in derby.
In attached patch 'd2998-6', I accept 'OVER ()' silently in sqlgrammar.jj. That
should change to accepting 'OVER <window name or spec>'. At the same time it
may be a good idea to throw an unsupported type exception if the user attempts
using a window name or specification?
Not having support for <window name or specification> is the reason for the
test not using the window name or specification as of now.
> Add support for ROW_NUMBER() window function
> --------------------------------------------
>
> Key: DERBY-2998
> URL: https://issues.apache.org/jira/browse/DERBY-2998
> Project: Derby
> Issue Type: Sub-task
> Components: SQL
> Reporter: Thomas Nielsen
> Assignee: Thomas Nielsen
> Priority: Minor
> Attachments: d2998-4.diff, d2998-4.stat, d2998-5.diff, d2998-5.stat,
> d2998-6.diff, d2998-6.stat, d2998-test.diff, d2998-test.stat,
> d2998-test2.diff, d2998-test2.stat
>
>
> As part of implementing the overall OLAP Operations features of SQL
> (DERBY-581), implement the ROW_NUMBER() window function.
> More information about this feature is available at
> http://wiki.apache.org/db-derby/OLAPRowNumber
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
