I want to prepare a demo for my client the financial training academy and they want to provide a fully functional demo of the software to prove we are not a scam. As the name suggests the company's most of the work would use financial and accounting. So, is this a good idea to use the SQL database that would be integrated in an actual framework or shall we go with the xml or dat files. What would be better? I need genuine answers please, no scams. Thank you.