What you can do is inspect Firebird structure and search for an unused area.
Documentation about this can be found at
http://www.firebirdsql.org/manual/fb-internals.html

By example if you check
http://www.firebirdsql.org/manual/fbint-standard-header.html

Pag_checksum: Two bytes, unsigned. Bytes 0x02 - 0x03. Checksum for the whole page. No longer used, always 12345, 0x3039. Databases using ODS8 on Windows NT do have a valid checksum here.

You can use this safely (?)

 

Mark Rotteveel wrote:

> On Windows, all files can have alternative streams with additional
> data. It is a form of hidden metadata that is attached to the main filename.

True, but the alternate data streams get lost when the file is stored
on a non-NTFS drive, sent via FTP/E-Mail etc. So depending on how the
software of the OP is released, this might not work well.

Anyway, rereading the original post, I realized that he is looking for
a platform independent solution, so my focus on Windows did not help
anyway.

Cheers,
Christian

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