Zoned-partitioning of tree-like access methods

摘要

The performance of access methods and the underlying disk system is a significant factor in determining the performance of database applications, especially with large sets of data. While modern hard disks are manufactured with multiple physical zones, where seek times and data transfer rates vary significantly across the zones, there has been little consideration of this important disk characteristic in designing access methods (indexing schemes). Instead, conventional access methods have been developed based on a traditional disk model that comes with many simplifying assumptions such as an average seek time and a single data transfer rate. The paper proposes novel partitioning techniques that can be applied to any tree-like access methods, both dynamic and static, fully utilizing zoning characteristics of hard disks. The index pages are allocated to disk zones in such a way that more frequently accessed index pages are stored in a faster disk zone. On top of the zoned data placement, a localized query processing technique is proposed to significantly improve the query performance by reducing page retrieval times from the hard disk.