Dieter, Thanks for the info! That looks like something small enough that it could be changed. There are a lot of applications that use write once tamper resistant technologies to guarantees data security is linked to physical security. With SQL databases, this is mostly done with a log file containing all the SQL commands, and is really only useful for checking later when one suspects that security has been compromised, or for rebuilding when there is file corruption. It is intriguing that Zope is so close to being able to use the actual live database file in this way. If this could be made to work, one might be able to guarantee against both illicit data alteration and accidental data corruption of the live data, to the tolerance levels of one's physical security. --Sean Hastings
-----Original Message----- From: Dieter Maurer [mailto:dieter@handshake.de] Sent: Sunday, January 25, 2004 6:24 PM To: Sean Cc: zope@zope.org Subject: Re: [Zope] Write Once Media with Data.fs?
Sean wrote at 2004-1-24 18:19 -0500:
I have noticed that the Data.fs file grows constantly. Does anyone know if the earlier part of the file is ever altered?
It is routinely:
When "FileStorage" starts to write a transaction record to the storage file, it marks the transaction status as "checkpoint" (status == "C").
After the complete transaction record is written, the transaction status is changed to " ".
Thus, you cannot place the storage file on a write once medium (unless you change the "FileStorage" code).
-- Dieter