Re: Proposal: QUALIFY clause

On 25/07/2025 14:55, Matheus Alcantara wrote:
> On Mon Jul 21, 2025 at 7:11 PM -03, Vik Fearing wrote:
>> SELECT a, b, c
>> FROM tab
>> QUALIFY wf() OVER () = ?
>>
>>
>> can be rewritten as:
>>
>>
>> SELECT a, b, c
>> FROM (
>>       SELECT a, b, c, wf() OVER () = ? AS qc
>>       FROM tab
>> ) AS q
>> WHERE qc
>>
>>
>> and then let the optimizer take over.  The standard does this kind of
>> thing all over the place; I don't know what the postgres project's
>> position on doing things like this are.
> With this transformation users will see a Subquery plan node even if
> it's not present on the original query, is that expected or it can be
> confusing to users?


This is a definition technique, it does not need to be implemented as a 
subquery.

-- 

Vik Fearing