New syntax to support the inclusion of the union operator within a view has been added to version 12.5. Note that the resulting view is not updatable, meaning that insert, delete and update operations are not allowed on views containing the union operator.
Component Integration Services supports union in views when proxy tables are referenced on either side of the union operator by forwarding as much syntax as possible to a remote site. This makes it possible to create a ’virtual table’ consisting of separate tables in Oracle and DB2, for example.
This feature is internal to ASE/CIS, and does not directly affect remote servers. However, when a statement is executed involving a view of this type, and all tables referenced by the view reside on the same remote server, the previously defined union capability will be examined to determine whether the union operator can be sent to the remote server.