I want to plug a 3rd party tool into the Data Loss Prevention database and do reports and other stuff.

Where can I get the database schema and descriptions of the tables, columns, indexes and linkage?

Also, are there any things in the database that might prevent me from accessing the data, like encryption of the data or numeric values for statuses instead of name?

Symantec does not support the use of 3rd party products using the Data Loss Prevention (DLP) database. 

Thus, the database schema and descriptions of the database elements and operation are not available to customers.

Symantec does not provide the Oracle database schema to customers. The schema is considered proprietary and altering it (for example, partitioning or changing indexing) would prevent our ability to support it. At this time, there are very few stored procedures. Most of the code is created and managed within the application

Nothing prevents a customer from using any number of database tools to determine the structure of the database.  Observation of the operation would probably reveal most of the design and operation of the database. 

A customer that decides to reverse engineer the DLP database must understand the following:

1. The database schema is not fixed.  It may change at any time without notice.
2. Most of the data is encrypted by the DLP process prior to insertion into the database.
3. There is no support for any issues with 3rd party use of the DLP database.