Record Users' SQL stmts & Their output

I want to record users' SQL statements and their output and store these data in a database. I want to complete the job with triggers. However, I don't know: 1. Which system catalog is used to store users' current SQL statements? 2. Is it safe to write an insert trigger in sysmaster? 3. How to avoid recurisive execution of the above trigger? 4. I can record SQL statements results with triggers, but is it possible to work out a method to do "Create trigger xxx before SELECT ..."? Or is there other methods to record the output of users' SELECT statements? 5. Is it possible to complete my subject with other solution except triggers? Hope someone can help me solve these questions. Any suggestion/help/hint are appreciated! -- Lin, Fu-Xiong -- Lin, FuXiong