Hi and grazie for your reply!
> If it's not an excercise, I think you don't need them
Not an exercise - I have to use the VIEW though - this was only a
sample. In real life the VIEW is trickier!
> select (select count(*) from t1) / (select count(*) from t2)::float
Looks as if the CAST was part of it.
Check here: https://dbfiddle.uk/?rdbms=postgres_10&fiddle=9a15766de01946d7f57b4298d8fb1028
Thanks for your input!
Pól...