Connection Qualifier

Connection qualifiers (also known as link qualifiers) allow several database links pointing to the same remote database to establish connections using different paths (such as Ethernet and modem). For example, a database can have two public database links to DBS1 that connect to the remote database using different paths.

• DBS1@ETHERNET, a link that connects to DBS1 using an Ethernet link

• DBS1@MODEM, another link that connects to DBS1 using a modem link

When you create a new master group, you can indicate that you want to use a connection qualifier for all scheduled links that correspond to the group. However, when you use connection qualifiers for a master group, Oracle propagates information only after you have created database links with connection qualifiers at every master site. For example, consider a multimaster configuration with two master sites, DBS1 and DBS2, and two master groups, MG1 and MG2. You want the group MG1 to use the connection qualifier ETHERNET and the group MG2 to use the connection qualifier MODEM. To accomplish this configuration:

• The DBS1 database must have database links DBS2@ETHERNET and DBS2@MODEM.

• The DBS2 database must have database links DBS1@ETHERNET and DBS1@MODEM.

• When you create the group MG1, indicate that you want to use the connection qualifier ETHERNET.

• When you create the group MG2, indicate that you want to use the connection qualifier MODEM.

You can specify a connection qualifier for a master site when you create a master group (Creating a Master Group).