Hi

> But then I noted that my database file was last modified yesterday

although I had worked on it several hours today (creating stored procedures.
I'm not sure if I made some data changes). Only when I disconnected all
clients from database, the file mod. date got updated. Where were the
updates stored until then, memory? some other file?.

Don't fear.
I assume, you have your server running on windows?
This is by design. To reduce load, windows updates file meta information
when closing the last open file handle to each file.
It is therefor common, that you file time get's updated only, when the
server completely releases that file. Anyway, it writes earlier... :D

> If there were power failure, would my work have been lost, or not?

Not in this scenario.

> Is there difference in this question between server and embedded version?

I can't tell for embedded, but since this is about windows file handling, it
should be the same.

Regards,
Steffen