Generate Hang analyze and System State dump.

Generated a system state dump and hang analyze for the period when the database is running slow.

connect / as sysdba;
oradebug setmypid
oradebug unlimit
oradebug hanganalyze 3
--wait 1 minute
oradebug hanganalyze 3
oradebug dump systemstate 266

oradebug tracefile_name # this just gives you the file name
exit