Single query optimization in tertiary memory

Abstract

We present query execution strategies that are optimized for the characteristics of tertiary memory devices. Traditional query execution methods are oriented to magnetic disk or main memory and perform poorly on tertiary memory. Our methods use ordering and batching techniques on the I/O requests to reduce the media switch cost and seek cost on these devices. Some of our methods are provably optimal and others are shown to be superior by simulation and cost formula analysis. 1 Introduction Large capacity storage systems are essential for an increasing number of scientific and commercial applications. For example, research on global change effects requires the storage and analysis of massive amounts of satellite data [STO91]. The Earth Observation System (EOS) [DOZ91] alone is expected to provide one terabyte per day of raw data to global change scientists. Such volumes of data require high capacity tertiary memory devices [KAT91] for storage and smart data base systems for efficient ...