Hi Fabio,
I believe we already discussed this problem and you were given the answer (see message #
1022212). If you want to have control over how many times and in which order expressions should be evaluated, use a loop. I am really surprised that you still can't understand a simple thing - If you are using SQL statement, query processor chooses algorithm, NOT YOU. Under different circumstances, the same SQL statement may be executed using different algorithms. If result of a SQL statement evaluation has any dependency on a particular algorithm chosen by the query processor, there is a bug in the SQL statement and you should fix it. If there is no dependency on a particular algorithm then it doesn't really matter how many times and in which order expressions are evaluated because this doesn't affect the result.
Thanks,
Aleksey.