On Fri, May 16, 2025 at 11:10:49PM +0200, Vik Fearing wrote:
> Isn't this a job for <fetch first clause>?
>
> Example:
>
> SELECT ...
> FROM ... JOIN ...
> FETCH SAMPLE FIRST 10 ROWS ONLY
>
> Then the nodeLimit could do some sort of reservoir sampling.
The query might return fewer than N rows. What reservoir sampling
requires is this bit of state: the count of input rows so far.
The only way I know of to keep such state in a SQL query is with a
RECURSIVE CTE, but unfortunately that would require unbounded CTE size,
and it would require a way to query next rows one per-iteration.
Nico
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