Advisor Webcast Feb 13th - Overview of the Database Service Cloud

Question

+++ Interesting for all APEX and SQL Developer experts +++
LIVE Advisor Webcast Wednesday, Feb 13th
Iloon Ellen-Wolff (Oracle) will give an "*Overview of the Database Service Cloud*".
The session consists of presentation and live demo, certainly there is room for questions and answers.
For more information - schedule, registration, session details - please check [Note 1508670.1|http://support.oracle.com/rs?type=doc&id=1508670.1]

Answer 1

Hi,
no, you got it wrong:
Oracle uses network services which are a logical representation of the database to resolve network requests.
in your ntsnames.ora file you have the following:
network_alias = my_alias -- here you can write anything you just need to resolve it correctly
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=TCP)
(host=hostname or IP)
(port=listener adapter port)
) -- this a complete socket information of the listener adapter!!
(CONNECT_DATA=
(SERVICE=your_service) -- this is what you tell the listener about the service you want to connect to. It is defined in the instance with the paramter service_names
In general it is network aliasses which are resolved with connect descriptor in the tnsnames.ora.
A connect decriptor consists of the address part + the connect_data part.
The address part is used to reach the listener.
The connect_data part is the information you hand over to the listener.
So the listener must know the service name.
The listener can either know this from the instance itself. When an Oracle instance is started it tries to registrer itself with a listener which listens on port 1521 for the protocol TCP.
The instance tell this listener two paramater values: INSTANCE_NAME and SERVICE_NAMES. Then the listener knows the instance and which services are defined. It is just a reprentation of the database to the listener.
If the listerner knows the service requested with a connect, it can establish a connection to a service handler. This could be a dedicated server process or a dispatcher.
Another mehtod to let the listener know the service requested is so called static regustration of the instance. This is made with an SID LIST in the listener.ora file.
Then the listener knows SID for the instance plus ORACLE_HOME and can find the executable to start a server process for a connect request.
Hope it helps a little-.
=;-)
If you have further questions pls do not hesitate to ask. O.K.?