数据库hang
set _prelim on
conn / as sysdba
或者
sqlplus -prelim "/ as sysdba"

通过oradebug hanganalyze命令分析数据库hang,同时需要系统状态转储文件
oradebug setmypid
oradebug unlimit
oradebug hanganalyze 3
oradebug dump systemstate 266
oradebug dump systemstate 266
oradebug tracefile_name
oradebug close_trace