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 --
