INFORMIX views

Greetings! A co-worker and I were discussing how INFORMIX handles a view on a table. I was under the impression that when you select off a view, INFORMIX merges the view criteria (ie, the WHERE clause) with your criteria and then executes the result. Therefore, if your criteria contained a GROUP BY clause, INFORMIX would merge the view criteria with your statement and execute the result as a single SELECT. My co-worker thinks that INFORMIX will first select the rows fitting the view being used and then perform your SELECT against the resulting temporary table. Could any of you shed some light on how INFORMIX handles a GROUP BY or ORDER BY clause in a SELECT against a view? Thank you, Ed