The C in ACID

I'm reading a new paper by David Lomet and Roger Barga, two respected (I think!) senior researchers at Microsoft, and come across the following in discussing the ACID properties of a DBMS:

"However, these techniques [Atomicity, Isolation, and Durable], which
are commonly known in the database technical community, do not entirely cope with the problem of consistency (C), which is primarily the responsibility of a user transaction to preserve."

If the meaning of this sentence is somewhat unclear, later in the paper they state:

"Recall that it is the user, not the database system, which provides
the "C" in "ACID" transactions."

...which seems to unequivocally indicate a complete confusion between the concepts of consistency and correctness. Or am I missing something?

The paper, "Recovery from Bad User Transactions" may be found here:

http://research.microsoft.com/db/immortaldb/

Scroll down to the bottom, its the first reference. Received on Mon Aug 21 2006 - 11:48:06 CDT