A Research on Transaction Schedule Algorithm of Security Database
|School||Harbin Engineering University|
|Course||Computer Software and Theory|
|Keywords||Multi-level security database Concurrency Control Covert channel Multi-level transaction|
In order to solve the problem of the security database transaction , multi-level transaction in the security database ACIS correctness criterion . And proposed transaction scheduling algorithm for multi-level multi-level security snapshot-based concurrency control algorithm and two-phase locking and serial Figure . The multi-level security snapshot-based concurrency control algorithm requires two snapshots are created in the database for each security level ( in addition to the system the highest security level ) , and all senior transaction accesses a snapshot of the database instead of direct access to low-level database . The introduction of a snapshot to avoid the problem of multi-level transaction scheduling algorithm in the covert channel and advanced transaction starve to death . Introduces the basic concepts of the snapshot and snapshot-based concurrency control algorithm , and the algorithm is proved to the implementation of the multi-stage transaction a serializable transaction history . In order to solve the conflict between the two-phase locking and security requirements , multi-level transaction scheduling algorithm based on two-phase locking and serial Figure restrict the scheduling of the two-phase locking within a single security level , and read in the Advanced Transaction lower data to eliminate the use of \Introduced serial map in order to ensure the consistency of the multi-stage transaction Affairs section on the different security level serialization order , in order to achieve the entire multi- level transactions can be serialized. Describes the algorithm implementation process, and prove the algorithm to meet the multi-level transaction A CIS correctness criterion . Finally, also studied the security database system design .