  In this paper, a visual language, VCP, for queries on complex-value databases
is proposed. The main strength of the new language is that it is purely visual:
(i) It has no notion of variable, quantification, partiality, join, pattern
matching, regular expression, recursion, or any other construct proper to
logical, functional, or other database query languages and (ii) has a very
natural, strong, and intuitive design metaphor. The main operation is that of
copying and pasting in a schema tree.
  We show that despite its simplicity, VCP precisely captures complex-value
algebra without powerset, or equivalently, monad algebra with union and
difference. Thus, its expressive power is precisely that of the language that
is usually considered to play the role of relational algebra for complex-value
databases.
