PG Doc comments form <noreply@postgresql.org> writes:
> The following documentation comment has been logged on the website:
> Page: https://www.postgresql.org/docs/17/sql-createfunction.html
> Description:
>> This is effectively another way of declaring a named OUT parameter
> Actually OUT works twice slower in compare to RETURNS TABLE
You stopped reading halfway through that sentence... it says
This is effectively another way of declaring a named OUT parameter,
except that RETURNS TABLE also implies RETURNS SETOF.
The difference between a set-returning and not-set-returning
function might explain what you're seeing, particularly because
the rules for inlining SQL functions are different in the two
cases.
A documentation comment is not the place to pursue this further,
but you could ask for help on our pgsql-performance mailing list.
regards, tom lane
