Re: Number of rows returned by Sort node

Vitaliy Garnashevich <vgarnashevich@gmail.com> writes:
> How, according to EXPLAIN ANALYZE, the Sort node could return more rows 
> as output (rows=767662), than it had for input from its child node 
> (rows=135627)?

Unsurprising when it's the inner input of a merge join --- that reflects
the merge join rescanning parts of the inner input.  It has to do that
whenever the outer input has duplicate keys.

            regards, tom lane