Preserve context before opening anything
- Copy the complete application and data directory, retaining names, timestamps and subdirectories.
- Record the original operating system, application name/version and how users selected the data set.
- Note similarly named files with index, memo, log or lock extensions.
- Hash the originals and perform all experiments on copies.
- Do not allow modern desktop software to “upgrade” or repair the file automatically.
Identification evidence
| Evidence | What it can reveal |
|---|---|
| Header bytes and embedded strings | Magic signature, engine/version markers, table names, code page or page size |
| Companion-file pattern | DBF memo/index family, Paradox table set, Btrieve/Pervasive dictionary or application-specific bundle |
| Record regularity | Fixed-length records, page structures, delimiters or compression |
| Executable imports/configuration | DAO/Jet, BDE, ODBC, Firebird, Btrieve or custom data-access dependencies |
| Known user values | Encoding, date representation and candidate field boundaries |
A controlled diagnostic process
- Run signature and string inspection without writing to the file.
- Group files by basename, timestamp and directory role.
- Inspect the application configuration and executable dependencies for database-engine clues.
- Try the most specific compatible reader against a disposable copy.
- Compare reported schema and record counts with known business expectations.
- Confirm memo/blob fields, deleted records and encoding before declaring success.
A plausible table preview is not sufficient identification. Different engines and versions may expose partial records while misreading field types, indexes or memo data.
What happens after identification
If the database is healthy, create a repeatable read-only extraction and document schema semantics. If damaged, preserve multiple copies and distinguish index damage from record-page damage. If the original application is required to interpret codes or calculations, analyze it alongside the data rather than exporting isolated tables.
See the legacy database hub for recovery and migration choices. The producing application may require software reverse engineering, especially when a proprietary container or unknown executable controls access.
Useful material to provide
- All files from the data and application directories
- Original software or screenshots
- Known example customer, product or transaction values
- Approximate record counts and date range
- Any prior repair or conversion attempts