Mirsaeid Hosseini - Department of Computer Engineering, Sari Branch, Islamic Azad University, Sari, Iran
Mehran Mohsenzadeh - Department of Computer Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Seyed Majid Hosseini Shirvani - Department of Computer Engineering, Sari Branch, Islamic Azad University, Sari, Iran

The large number of applications manages time varying data. Existing databasetechnology seldom supports temporal database, TDB, according to time aspects.These intrinsic temporal database applications rely on such database which storesand retrieves time referenced data. Moreover, applications need to be managed oncommon data items access simultaneously and to be precluded from inconsistencyas soon as possible which is the main task of concurrency controller or CC in short.The method used by CC in typical DB differs from its attitude with TDB. The varietyalgorithms were proposed regarding to TDB properties by reduction of granule sizeand decreasing the rate of conflicts to satisfy good performance, but none of themhas achieved robust results. There are two categories of CC such as pessimistic andoptimistic. In this paper new approach, with considering the TDB aspects, based onoptimistic method has been suggested. It reclines the size of granule as data itemappropriately and recognizes the conflicts swiftly. Consequently, we compare ourproposed algorithm with pervasive 2PL-pessimistic approach. The outcome showsthat new proposed algorithm has high degree of trade off with satisfying nearconflict time detection and high rate of parallelism metrics.

Temporal Database, Concurrency controller, 2PL-pessimistic, time varying data