Disk Performance in a Transaction-Oriented System
Daniel P. Heyman, Shalom Tsur⋆ · SIAM Journal on Computing · 1984
In this paper we address the performance issues that arise as a result of the two level scheduling in a database/operating system. At the upper (database) level transactions are logically scheduled so as to maintain the database integrity. At the lower (operating system) level physical disk requests are scheduled.We consider the performance problems that result from the interplay between these two levels of scheduling. Our model assumes the existence of a dictionary that must be consulted prior to the execution of a transaction. We derive the optimal disk placement of this dictionary and our results show that the waiting time for dictionary look-up is the critical component in the transaction response-time for a wide range of transaction sizes. To alleviate this problem we suggest alternative approaches to dictionary placement in such systems.