On 16/05/2025 23:21, Tom Lane wrote:
> Vik Fearing <vik@postgresfriends.org> writes:
>> On 16/05/2025 15:01, Tom Lane wrote:
>>> Seems to me the obvious answer is to extend TABLESAMPLE (or at least, some
>>> of the tablesample methods) to allow it to work on a subquery.
>> Isn't this a job for <fetch first clause>?
>> FETCH SAMPLE FIRST 10 ROWS ONLY
> How is that an improvement on TABLESAMPLE? Or did the committee
> forget that they already have that feature?
>
> TABLESAMPLE seems strictly better to me here because it affords
> the opportunity to specify one of several methods, which seems
> like it would be useful in this context.
TABLESAMPLE is hitched to a <table primary> which can be basically
anything resembling a relation. So it appears the standard already
allows this and we just need to implement it.
--
Vik Fearing
