Log msg

How to config log file to log statement without CONTEXT stuff?
I want log query, but not the detail unless there is a problem, e.g.
Delete aaa from mytable where mysqlfunction(bbb);
I want log this statement, but not any CONTEXT inside mysqlfunction,
because it will easily filled up my disk if mytable have millions of
entries, meanwhile, the log file become useless.
But if I set log_statement = true, log file will log millions of
statement in mysqlfunction, but I set log_statement=false, log file
won't log query at all.
Simply say, I want log what I execute(my query), but not how execute
(process) .

Jie Liang