From the docs...

"CGA - Call Global Area - created at the beginning of a call, exists for the duration of that call and is freed at the end of call. If a process is currently runnning, there is one and only one CGA for every PGA. If a process is not currently running, there is no CGA within its PGA."

See http://support.oracle.co.uk/metalink...&p_id=121505.1

For more info

Regards