Hi, On 2019-05-23 18:31:43 -0400, Tom Lane wrote: > Andres Freund <and...@anarazel.de> writes: > > It's also noticable that we preposterously assume that the sort actually > > will return exactly the number of rows in the table, despite being a > > top-n style sort. > > In general, we report nodes below LIMIT with their execute-to-completion > cost and rowcount estimates. Doing differently for a top-N sort would > be quite confusing, I should think.
I'm not quite sure that's true. I mean, a top-N sort wouldn't actually necessarily return all the input rows, even if run to completion. Isn't that a somewhat fundamental difference? Greetings, Andres Freund
