An Oracle database is represented to clients as a service ; that is, the database performs work on behalf of clients. A database can have one or more services associated with it. Figure shows two databases, each with its own database service for intranet clients. One service, sales. Another service, finance. The sales and finance databases are each identified by a service name , sales. In the case of sales. A database can have multiple services associated with it. Figure shows one database that has two different services for Web clients.
Understanding Database Instances
Database Service and Database Instance Identification
Summary : in this tutorial, you will learn about the Oracle database link and how to create a database link to a remote Oracle Database server. A database link is a connection from the Oracle database to another remote database. A database link allows a user or program to access database objects such as tables and views from another database. Once you create a database link, you can access the tables or views from the remote database using the following pattern:. For example, you can query data from a table in the remote database as if it was in the local server:.
Configuring Advanced Network Address and Connect Data Information
These are useful when the application maintains a single user session to a database. Connection pooling is important for performance when applications frequently connect and disconnect from the database. Small pools can also be useful for applications that want a few connections available for infrequent use. SessionPool at application initialization time, and then SessionPool. These include limiting the amount of time that opening a connection can take, or enabling network encryption. Connections should be released when they are no longer needed by calling Connection. Alternatively, you may prefer to let connections be automatically cleaned up when references to them go out of scope. This code ensures that, once the block is completed, the connection is closed and resources have been reclaimed by the database.
In the following example, sales. To add a network protocol address to an existing net service name or database service:. Select either a net service name or a database service. The right pane displays the current destination service and address list. See Also: Oracle9i Net Services Reference Guide for details about protocol address parameters Order the protocol addresses according to where they should be in the protocol address list with the left-arrow and right-arrow buttons. Unless multiple address options are configured, the first address in the list is contacted.