The Automatic System Facility › Data Tables › Views

Views

Views are data tables that are derived from one or more existing stored tables or non-SQL defined records. By defining a view, you can combine several tables or records and present them as one table. Alternatively, views also enable you to select certain columns and rows from stored tables and records. By defining a view, you can create a table that presents a subset of information in the database.

When a view is accessed, data is retrieved directly from the source tables or records. Thus, a view always presents a current picture of data stored in the database. Source tables and records can be modified through a view if the user has the authority to do so.

Using

Views can be used to:

• Apply security. A view can be defined for a user that contains only certain columns or rows of data, rather than the entire source table or record.
• Combine several tables or records in order to display them as one relational view.
• Analyze data based on the relationships between tables or records.
• When a user has update authority, modify several source tables or records through one online transaction.

Creating

Views can be created in two ways:

• Using ASF, an end user can define views of data tables created through ASF, CA OLQ, CA Culprit, or the Information Center Management System (CA-ICMS). Additionally, a programmer or DBA can define views of records (defined through the schema compiler) that have been made available to ASF.
• Using the subschema compiler, a DBA can define logical records; these logical records represent views of records.

Limits on Use

Views created through ASF can be used in ASF as source tables for other views. Logical record views created through the subschema compiler cannot be used in ASF as source tables for other views. Likewise, you cannot derive views from views derived from non-SQL defined records.