Re: Request for Patch Feedback: Lag & Lead Window Functions Can Ignore Nulls

On Fri, Jun 21, 2013 at 6:29 PM, Troels Nielsen <bn.troels@gmail.com> wrote:
> The grammar conflict appears to be because of ambiguities in:
> 1. table_ref (used exclusively in FROM clauses)
> 2. index_elem (used exclusively in INDEX creation statements).
>
> Now, this doesn't seem to make much sense, as AFAICT window functions
> are explicitly disallowed in these contexts (transformWindowFuncCall
> will yield errors, and I can't really wrap my head around what a
> window function call would mean there).
>
> I therefore propose a simple rearrangement of the grammar,
> syntactically disallowing window functions in the outer part of those
> contexts (a_expr's inside can't and shouldn't be done much about)
> which will allow both RESPECT and IGNORE to become unreserved
> keywords, without doing any lexer hacking or abusing the grammar.

I reviewed this today and I think this is a very nice approach.
Thanks for working on it!

-- 
Robert Haas
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