eXceed69 2 Posting Pro

I'm having some issue figuring out our backend database. This project was assigned to me few weeks now but no tech document. All I can do is pull all the table name via this query "select * from all_tables". This was been a big issue as it ate time due trail and error. I've already brought this but no response. So, I have to initiate something..so how can I do that?