[From Oracle FAQ
One of the primary tests for DBMS reliability is what's known as the ACID test. ACID-compliant systems are as close as you can get to guaranteed not to lose your data. Essentially, as long as your database files are intact, you are guaranteed that your data is consistent. This is not true for non-ACID compliant systems. Non-ACID-compliant systems are vulnerable to data inconsistency, and generally aren't taken seriously for any application where data integrity is important. Now, in 10gR2, Oracle offers us the option to break its ACID compliance.
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