Ensuring atomicity is a major outstanding problem with present methods of handling multilevel transactions. The chief difficulty is that a high section of a transaction may be unable to complete due to violations of the integrity constraints, and a rollback of sections can be exploited to implement a covert channel. We define a notion of semantic atomicity which guarantees that either all or none of the sections of a transaction are present in any history. The notion of correct executions in our model is based on semantic correctness-that is, maintenance of integrity constraints-rather than serializability. We give a method whereby the application developer can statically analyze the set of transactions in the application and determine if the set ensures semantic atomicity and other desirable properties.
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