It is impossible to compare these Oracle tables with Informix tables.
Just to give you an example:
Every connection to an Oracle instance is translated into a process. In Informix it is translated into a thread.
This means that a session is (syssessions) is allocated to a thread, named sqlexec.
check with onstat commands to descipher all this.
What is an Oracle banner?
For the machine name you will have to create a stored procedure
with system 'uname' in it.