marcos sicat <marcos.sicat@atlasifs.com> writes:
> The function is the same between v15 and v17. Is there a subtle difference in performance for nested subqueries in
v17?
Your next step should be to compare the plans for the function's
query. The auto_explain or pg_stat_statements extensions could
be used to check that in-situ, if manually EXPLAINing that query
doesn't yield insight.
regards, tom lane