Wednesday, August 3, 2011

Describing contents of SQLNet.ora file




In environments where the client often requests names from a specific domain, it is appropriate to set a default domain in the client sqlnet.ora file with the NAMES.DEFAULT_DOMAIN parameter.

For eg:

When a default domain is set, it is automatically appended to any unqualified net service name given in the connect string, and then compared to net service names stored in a tnsnames.ora file or Oracle Names server.

CONNECT scott/tiger@sales
In this example, sales gets searched as

EZCONNECT is the easy connect protocol, available in 10g, whenever you want to connect to a database without tnsnames.

C:\>sqlplus scott/tiger@//ss01:1521/sales

HOSTNAME was the old-fashion way to connect to a database, where hostname = sid and port = 1521. In this regard EZCONNECT is just an extension of the hostname method.

Entry of IP address and server name is updated in 

C:\WINDOWS\system32\drivers\etc\hosts file

And last TNSNAMES.ORA is the most common way we all know.

ONAMES (desupported now) is a centralized naming method where connection information is stored in a centralized directory server.

Local naming is suitable when you have small amount of clients as adding/changing database connection information will result in changing the tnsnames.ora file on each client. If you have large amount of clients you might want to look at centralized naming.

In centralized naming, changes are made only in the directory server and clients see the new information when making a connection.


NTS means that Oracle can rely on NT native authentication. When this
is set, a member of the ORA_DBA group can log in to Oracle as SYSDBA
without a password. A setting of NONE means that Oracle relies on a
valid username & password being supplied.