I would like to know more about Control-M Enterprise Manager and Control-M Server Database, Tables and Columns etc.
Where can I download the latest Control-M Database Schema and Port Diagrams?

The latest version is attached to this Knowledge Article,  The following video demonstrates how to access the site and download the older versions:

- The Control-M DB Schema's and Port Diagrams can be found on the BMC FTP server ftp.bmc.com
- Directory: /pub/control-m/opensystem/DB_Schemas

Below are instructions to download the Control-M Database Schema from the BMC FTP Site:
NOTE:  New bowers block FTP access.  It is necessary to use an ftp client such as from command line in the example below, or a third party FTP client such as FileZilla or WinSCP, rather than from a web browser.

Connect to BMC FTP server from command console
1. Open a windows command prompt.
2. Execute "ftp ftp.bmc.com"
3. Log in as "anonymous" and use your e-mail as your password.
4. Navigate to the directory by executing the command:   cd pub/control-m/opensystem/DB_Schemas
5. List all the Database Schema available for download, execute: ls
6. Navigate to the required directory using the cd command.  For example, "cd 800_ERDs"
7. Change to binary mode, by executing: bin
8. Change to hash mode to ensure the downloading is progressing, by executing: hash
9. Download the chosen file(s), using the get or mget command
For example:  get BMC_Control-M_Workload_Automation_DB_Posters_v8.zip

CAUTION:
The data schema is for your reference only. Updating the database using SQL can impact data integrity. BMC strongly discourages customers from running SQL against the active database unless instructed by development. Data integrity is of outmost importance to the application violating any aspect of data integrity well impact the functionality of the application.