> Tatsuo Ishii <ishii@postgresql.org> writes:
>>> The latest version restricts it to lag, lead, first_value, last_value,
>>> and nth_value. We can extend it in a subsequent patch if there's
>>> demand?
>
>> The restriction is required by the SQL standard. So I don't think we
>> need to extend to other window functions.
>
> The SQL spec does not believe that user-defined window functions are a
> thing. So its opinion on this point is useless.
Of course the standard does not mention anything about the user
defined window functions and the restriction is not apply to the user
defined window functions.
> I would think that
> IGNORE NULLS is potentially useful for user-defined window functions,
> and we should not be building anything that restricts the feature to
> specific functions.
So you want to allow to use IGNORE NULLS to other built-in window
functions?
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp
