We have released a data dictionary for ServiceDesk 7.1 SP2. The full article can be found here http://www.symantec.com/docs/HOWTO77292 .
Aside from the ServiceDesk specific tables, this data dictionary can also be used for Workflow 7.1 SP2.
All ServiceDesk reportable data is stored in the Process Manager database. The Process Manager database holds data that is required for general Process Manager database operations. This instruction provides information about the tables that commonly hold reported data and the relationship of these tables to each other.
Tables in the Process Manager database
Tables
Description
Item Base Tables
These tables contain base data about an item.
Item Detail Tables
These tables contain additional details for Item Base Tables.
Process Data Tables
These tables contain process data for ServiceDesk or custom processes.
These tables are expressed as ProcessProfiles in the Process Manager portal.
Reference / Relationship Tables
These tables are used to manage the relationship between records without adding additional detail fields.
Several common keys are used to link records across these different tables. Depending on the table, the key fields in the table may have different names than their key values. Use these key field types to link the various tables.
Main types of key fields in the tables
Key field
SessionID
Sometimes called the WorkflowTrackingID.
This field is a GUID that is unique to each instance of a Workflow or ServiceDesk process.
ProcessID
A sequential number
This field is the TicketID for a ServiceDesk process and the ReportID for a custom Workflow process.
For example, IM-00003 is the TicketID number for an incident in the Incident Management process in ServiceDesk.
UserID
Generally, the GUID ID for the user
Does not apply to the default admin and guest user accounts.
If the user comes from Active Directory, the UserID is the same UserID GUID from Active Directory.
UserPrimaryEmail
The primary email address for the user on record.
TaskID
A GUID that is unique to each task.
A single SessionID can have many tasks, but a task can only report to a single SessionID.
GroupID
A GUID ID for a Process Manager group.
Tasks can be assigned to either users or groups.
For the full list of tables and fields please use the how to article http://www.symantec.com/docs/HOWTO77292