Referencing an External Schema

You can reference a different schema than the default schema to fetch a table. To reference an external schema, the default schema must have the proper access privileges. The privileges are set on a command line.

The ways for granting access privileges vary according to different databases. In the following syntax, database_username refers to the default schema in the create_user.sql statement.
Oracle Database
Log in as system and grant the create any trigger and drop any trigger permissions to the user. For example, 
grant create any trigger to adb_schema
grant drop any trigger to adb_schema
Sybase Database
Use the following command before creating catalog tables for the external schema:

sp_role "grant", sa_role, adb_schema

In addition, Oracle and Sybase users must have permission to access a source table in an external schema. If table relationships are used, the SELECT permission is required for both parent and child tables. The SELECT, INSERT, UPDATE, and DELETE permissions are required for accessing a destination table in an external schema.

SQL Server Database
Log in as sa and then use the following command before creating catalog tables for the external schema: 
use master
EXEC sp_addsrvrolemember 'adb_schema', 'sysadmin'
DB2 on IBM i/AS400
You can avoid table access problems by changing the ActiveDatabase user authority to *ALLOBJ.