sql - What do OrientDB's functions do when applied to the results of another function? -

i getting strange behavior on 2.0-m2. consider following against gratefuldeadconcerts database:

query 1

select name, in('written_by') wrote v type='artist' 

this query returns list of artists , songs each has written; majority of rows have @ least 1 song.

query 2

now try:

select name, count(in('written_by')) num_wrote v type='artist' 

on system (osx yosemite; orient 2.0-m2), see 1 row:

name           num_wrote --------------------------- willie_cobb    224 

this seems wrong. tried better understand. perhaps count() causes in() @ written_by edges...

query 3

select name, in('written_by') v type='artist' group name 

produces results similar first query.

query 4

now try count()

select name, count(in('written_by')) v type='artist' group name 

wrong path -- try let variables...

query 5

select name, $wblist, $wbcount v  let $wblist  = in('written_by'),      $wbcount = count($wblist)  type='artist' 

produces seemingly meaningless results:

you can see $wblist , $wbcount columns inconsistent 1 another, , $wbcount values don't show obvious progression cumulative result.

note strange behavior not limited count(). example, first() odd things.

count(), in rdbms, computes sum of records in 1 value. purpose .size()seems right method call:

in('written_by').size()