A maintenance object is meta-data that defines a group of tables that make up a logical entity. Maintenance object meta-data exists for every object in the system. For example, there is a maintenance object called USER . This maintenance object's tables hold the information about your users.
When you submit a background process to compare the tables in two databases, you don't tell the process about the individual tables. Rather, you define the maintenance objects that you want compared and the system uses the maintenance object meta-data to determine the physical tables to compare (note, this is not 100% true, please see Database Processes Define The MOs To Compare for the complete story).
Please notice that the USER maintenance object has a single Primary table and multiple Child tables. This is true of virtually every maintenance object in the system (i.e., all MO's have a single Primary table and 0 to many Child tables). Each instance of a given maintenance object has a single row on the Primary table, and zero or more rows on each Child table.
The base package is shipped with all maintenance object and table meta-data populated. You will not have to change this meta-data unless your implementation has introduced new tables.
Copyright © 2011, Oracle and/or its affiliates. All rights reserved.