IBM InfoSphere Federation Server, Version 10.1

Working with nicknames

A nickname is an identifier that an application uses to reference a data source object, such as a table or view. In a federated system, you use can nicknames to access data source objects and improve the performance of queries on remote data sources.

Nicknames in a federated system
When you want to select or modify data source data, you query the nicknames by using the SELECT, INSERT, UPDATE, and DELETE statements. You submit queries in DB2® SQL to the federated database.
Restrictions on nicknames
The federated server does not support user-defined types, distinct types, and reference types as columns of nicknames.
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.
Creating nicknames over temporal tables
Federation support of temporal tables gives you the ability to create a nickname over a remote temporal table.
Accessing new data source objects
To access new data source objects, you must create nicknames for them. Use the CREATE NICKNAME statement for data sources that do not have nicknames.
Accessing data sources using pass-through sessions
You can submit SQL statements directly to data sources by using a special mode that is called pass-through. The pass-through session allows you to submit SQL statements in the SQL dialect for that data source.
Accessing heterogeneous data through federated views
A federated view is a view in the federated database whose base tables are located at remote data sources. The federated view references base tables with nicknames, instead of the data source table names.
Creating a nickname on a nickname
You can create a nickname on a nickname.
Selecting data in a federated system
How you select data in a federated systems depends on the type of data source that you select from.
Specifying informational constraints on nicknames
Informational constraints on nicknames can improve the performance of queries on remote data sources.
Updating nickname statistics
Retrieving the statistics for a nickname ensures that the query optimizer is using the most recent information about the nickname when it generates the query access plans.

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Last updated: 2012-05-18