Re: popcount

You bring up an excellent point, which is that our builtin functions
could use a lot more documentation directly to hand than they now
have.  For example, there's a lot of needless ambiguity created by
function comments which leave it up in the air as to which positional
argument does what in functions like string_to_array, which take
multiple arguments. I'll try to get a patch in for the next CF with a
fix for that, and a separate one that doesn't put it on people to use
\df+ to find the comments we do provide. There have been proposals for
including an optional space for COMMENT ON in DDL, but I suspect that
those won't fly unless and until they make their way into the
standard.