I'm curious to know the answer to this, but to give you a better understanding of that area - this question reminds me of dmcghan's post
You might be able to look into the sessions using v$session
client_identifier will be something like: nobody:6419832222161
Action: Processes - point: AFTER_HEADER
Module: APEX_040200/APEX:APP 4550:1
and check out some of the other columns in regard to it's state - how do you know it's a deadlock?
Thanks for the link, Scott. That is a very interesting post. I tried placing a commit in the application process think that would release any locks but it doesn't seem to make a difference.
I can tell I am getting a deadlock because, when the second page tries to load I get the message "ORA-00060: deadlock detected while waiting for resource" I can also see the lock information in the v$session view, I just need to figure out how to decipher it.
I am also certain that it has something to do with the collections because, if I comment out the code that manipulates them in either the application or the page process I don't get the error.
I also should mention that we are on Apex 4.0. Unfortunately we tried upgrading to 4.2 about two months ago but it broke quite a few things so that project was put on hold.
If it's collections related, it may be a bug.
Perhaps put an example on apex.oracle.com, maybe one of the apex dev team can spot something.