Check that the query is correctly designed
Check your memory sizing
Check your I/O configuration (asynchronous?)
Check your OS kernel parameters as well as your Oracle parameters
Do you have direct I/O ?
(also have a look at post #29 of
this thread )
Any error message in the alert<DB_SID>.log ?
Get in touch with your Oracle DBA and ask him (or get it on your own) , the corresponding
Oracle Installation Guide, you will find some sizing requirements as well as rule of thumb and advice for parameter tuning (also for some of your OS kernel parameters).
Any other appli running on that superdom ?
Is this oracle instance a new install or does it run for a long time and suddenly has performance issue ?
Are you running PA-RISC or Itanium?
You might also read
this and read carefully the OS-Tuning and Kernel Tuning part on page 18 (and of course also the rest of the document ...
)
You might want to work closely with your DBA if you are not familiar with oracle because this kind of troubleshooting may require OS+DBA knowledge.
Also ask your DBA if he has activated the automatic SGA and PGA management (he should, since those functionnalities are available in your oracle version)