Mohammad Shabanali Fami - Islamic Azad University
Elham Shabanali Fami - Isfahan university of technology
Mohammad Ali Montazeri - Isfahan university of technology
Mohammad Taghi Isaai - Sharif university of technology

Temporal database is one of the most common types of databases. Portfolio management, accounting, storage, treatment management systems, aerology systems and scheduling are applications which their data have time references. Temporal nature of data and increasing size of temporal databases due to non-removal data requires presenting a solution to overcome this limitation. In this research, firstly the current model of vacuuming systems are simulated and analyzed. Then the proposed model introduced for vacuuming systems using distribution concepts. This model is simulated in the same conditions with current model. Using experimental results, advantages and disadvantages of both models were investigated. The proposed model is more capable than the current model in answering temporal queries. Its response time to temporal queries is less than the current model. But the proposed model's cost is more than the current model. Considering the possibility of idle resources usage in organizations, these costs can be ignored along with optimize usage of facilities

vacuuming, Multiclass queuing model, Schema versioning, temporal database