- Product: Aleph
- Product Version: 22, 23
- Relevant for Installation Type: Dedicated-Direct,Direct,Local,Total Care
What does it mean, if the Oracle listener status (util O / 2 / 4) shows status 'UNKNOWN'?
Service "aleph22.alephserver.xxx.com" has 2 instance(s).
Instance "aleph22", status UNKNOWN, has 1 handler(s) for this service...
Instance "aleph22", status READY, has 1 handler(s) for this service...
Oracle's explanation for the "UNKNOWN" status handler is this -
"An UNKNOWN status means that the instance is registered statically (with a SID_LIST) in the listener.ora file rather than dynamically with service registration. Therefore, the database status is "not known" to the listener. There is no reason a connection cannot be made, however, using the SID value.
For normal communication, the SID_LIST in the listener.ora file is not required. One of the reasons why Oracle recommends not using one, is because it may cause un-necessary overheads on the listener process. The SID_LIST section only needs to be used for instances such as PLSExtProc or if older OEM tools are in use. It is not normally a problem having the instance duplicated in the SID_LIST, but it is preferable not to have it."
We have the SID_LIST configured to specify ORACLE_HOME in listener.ora, like this:
Thus the overhead. But the application should have no problem to connect to the database using SID