See the first part of this post here: HANGANALIZE Part 1.
This post is just complement with a little kludge I liked…
First, let’s remmember that the hanganalyze is used when you are if some hanging in your environment, of course.
But what if you are having difficult to access the database, even with ‘/ as sysdba’?
You can create a ‘preliminary connection’ without create a session, like this:
sqlplus -prelim / as sysdba
This ‘feature’ is available since Oracle 10g, and it basically skips a session creation part (which could block) when logging on as SYSDBA.