A file with .dfg extension is a Spreadsheet file created by Interscape Inc. for Interscape Data Flask software. Data is populated in DFG files in rows and columns. Data Flask is a Spreadsheet software, designed to retain data types, source, and key information. It can migrate tables and indexes by changing only the connection string. It offers features such as VBScript command line, VBScript formulas, and macros along with SQL scripts for updating and migration of data. DFG files are saved as binary files to disc and can be opened with Interscape Data Flask software.
DFG File Format - More information
DFG files save spreadsheet data information as binary files to disc. The internal data structure and format details of these files is not known however.