Accessing data with nicknames
With a federated system, you can easily access data, regardless of where it is stored. To access data, you create nicknames for your data source objects, such as tables and views.
For example, if the nickname DEPT represents the remote table EUROPE.PERSON.DEPT, you can use the statement SELECT * FROM DEPT to query information in the remote table. When you query a nickname, you do not have to remember the connection details about the data source. Thus, you do not need to be concerned with these issues:
- The name of the object at the data source
- The server on which the data source object resides
- The data source type on which the object resides, such as Informix® and Oracle
- The query language or SQL dialect that the data source uses
- The data type mappings between the data source and federated server
- The function mappings between the data source and federated server
The underlying metadata in the federated database catalog provides the federated server with the information that it needs to process your queries. This metadata is gathered from the data sources when the federated server and database are set up and configured to access the data sources.
After the federated system is set up, you use the nicknames to query the data sources or to further enhance the federated system configuration.