Question: Which of those documents is the oldest? | which kind of information the oldest documents do you want me to give you? | Give me the document name from those documents that has the earliest document date.
SQL: SELECT document_name FROM Documents AS T1 JOIN projects AS T2 ON T1.project_id   =   T2.project_id WHERE T2.project_details   =   'Graph Database project' order by document_date limit 1