I recommend that anyone seriously interested in transaction processing
read "Transaction Processing: Concepts and Techniques" by Gray and
Reuter, at least chapters 1 through 7, and chapter 10 "Transaction
Manager Concepts".
Chapter 7 "Isolation concepts" presents the main isolation theorems in
an easy mathematical form. When you read the theorems and their proofs,
you will notice that there is NO MENTION OF RELATIONAL DATABASE
STRUCTURES. Thus we're talking about OBJECT TRANSACTION PROCESSING.
As to consistency in ACID, here's a passage from page 166 in chapter 4
"Transaction models":
>>Consistency:
>>A transaction produces consistent results only; otherwise it aborts. A result is
>consistent
>>if the new state of the database fulfills all the consistence constraints of the
>application;
>>that is, if the program has functioned according to specification. Simpley as that
>may seem,
>>it has a number of subtle ramifications ...
>>Here, then, is the other way to put it: data is consistent if it has been produced
>>by a committed transaction. This is where (in today's systems at least) the
>definition
>>becomes somewhat circular. ...
>>It is important to keep in mind that the consistency definition that comes with the
>>transaction paradigm is largely a syntactic one.
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
