Accessing an ADD data dictionary record definition is identical to accessing a data dictionary table or view definition in an Oracle database. You issue a SQL SELECT statement that specifies a database link. The data dictionary view and column names of the Oracle database server are used to access the gateway data dictionary. Synonyms of supported views are also acceptable.
For example, the following statement queries the data dictionary table ALL_TABLES:
SQL> SELECT * FROM ALL_TABLES@IMS;
When a data dictionary access query is issued, the gateway:
- Maps the requested table, view, or synonym to one or more ADD data dictionary names.
- Processes the query within the gateway.
- Might convert the retrieved data to give it the appearance of the Oracle database server data dictionary table.
- Passes the data dictionary information to the Oracle database server.