Oracle7 Server Distributed Systems Volume I: Distributed Data

Schema Object Names and Data Access

Oracle allows schema objects (for example, tables, views, and procedures) throughout a distributed system to be referenced in SQL statements using global object names. In Oracle, a schema object's global name consists of the name of the schema that contains the object, the object name, followed by an "at" sign (@), and a database name. For example, the following query selects information from the table named SCOTT.EMP in the SALES database:

SELECT * FROM scott.emp@sales.division3.acme.com;

Oracle does not check, nor enforce, unique global object names when an object is created. Oracle does not store complete global object names in the distributed data dictionaries. However, Oracle does guarantee that an object name is unique within its own local database. Additionally, a distributed system can be configured so that each database within the system has a unique database name, thereby providing unique global object names.