The concurrency control protocol that has been implemented in the commercially available Trusted Oracle multilevel secure database management system (DBMS) generates histories that are level-wise serializable. Level-wise serializability suffers from the inconsistent retrieval problems which may seriously harm database integrity. The authors show that it is possible to meet stricter correctness criteria using Trusted Oracle, provided knowledge of the update transactions that will be executed in the system is available. They perform a static analysis of the read- and write-sets of these transactions and, based on this analysis, control the order of submission of the transactions to the scheduler in such a way that the resultant history ensures higher correctness level. The exact order chosen depends on the level of consistency desired. The goal is achieved without modifying the Trusted Oracle concurrency control algorithm in any way.
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