Oracle: DBMS_COMPARISON package

An interesting feature for Oracle 11g is DBMS_COMPARISON package which planned to use compare data within two schemas or between database`s schema.
To use DBMS_COMPARISON you have to grant. If you connected as SYSDBA you already have had grant to execute. Other users need execute grants on DBMS_COMPARISON and that user will need to be granted execute catalog role too.
Note: The database character sets must be the same for the databases that contain the database objects being compared.
For all scan modes to be supported by the DBMS_COMPARISON package, the database objects must have one of the following types of indexes:
o A single-column index on a number, timestamp, interval, or DATE datatype column
o A composite index that only includes number, timestamp, interval, or DATE datatype columns. Each column in the composite index must either have a NOT NULL constraint or be part of the primary key.
For the scan modes CMP_SCAN_MODE_FULL and CMP_SCAN_MODE_CUSTOM to be supported, the database objects must have one of the following types of indexes:
 a single-column index on a number, timestamp, interval, DATE, VARCHAR2, or CHAR datatype column.
 a composite index that only includes number, timestamp, interval, DATE, VARCHAR2, or CHAR columns. Each column in the composite index must either have a NOT NULL constraint or be part of the primary key.
The DBMS_COMPARISON package can compare the following types of database objects:
• Tables
• Single-table views
• Materialized views
• Synonyms for tables, single-table views, and materialized views
The DBMS_COMPARISON package supports all Oracle data types (VARCHAR2, NVARCHAR2, NUMBER, FLOAT, DATE, TIMESTAMP etc) except the following:
LONG
LONG RAW
ROWID
UROWID
CLOB
NCLOB
BLOB
BFILE