most important is the database monitor (STRDBMON with all details). To analyze the results, you would have to use Ooops Nerv. This will show up all informations about all SQL workload you did run the monitor.
SQL running from clients (ODBC, JDBC, ADO, DRDA and SQLCLI in server mode), you will see the serverjobs QZDASOINIT and one of the QPWxxx Jobs.
Local access to the database via embedded SQL STRSQL, QMQRY are hard to seperate from RLA accessat the first glance.