With the help of this question I finally managed to enable sqlite3_trace in my iPhone application.
Now, I have noticed that after being enabled, sqlite traces every statement, even outside the scope of the function I have enabled it.
Not much of a trouble but I am wondering whether there is a way to switch it off for other statements leaving it on for some specific ones?
I think if you call sqlite3_trace again and pass NULL for the callback function-pointer, then that should disable tracing.