The status UNKNOWN will show for any service that was created based on
SID_LIST in the listener.ora.
These such services do not have the functionality to report status to
the listener. The newer method of service registration with the use of
PMON will in fact create service handlers for the database that do in
fact report thier status on a regular basis to the listener process.
Since the older SID_LIST handlers were not coded with that
functionality they simply report as UNKNOWN in the listener display.
So its nothing to be alarmed by its simply the older code cannot do
what the newer code can.
The SID_LIST section only needs to be used for instances such as
PLSExtProc.
It is not normally a problem having the instance duplicated in the
SID_LIST, but it is preferrable not to have it.
One of the reasons why Oracle recommends not using one, is because it
may cause un-necessary overheads on the listener process.
The PMON registration cycle is every 1 minute. Along with the instance
information, it also updates the listener with the Dispacthers load.
Received on Mon Mar 22 2004 - 01:23:21 CST
