Computer Science Department
School of Computer Science, Carnegie Mellon University
Lachesis: Robust Database Storage Management
Based on Device-specific Performance Characteristics
Jiri Schindler, Anastassia Ailamaki, Gregory R. Ganger
To appear in a revised form in the
Proceedings of the Conference on Very Large Databases,
VLDB03, Berlin, Germany, September 9-12, 2003.
Keywords: Database storage management, performance evaluation
Database systems work hard to tune I/O performance, but they do not
always achieve the full performance potential of modern disk drives.
Their abstracted view of storage components hides useful
device-specific characteristics, such as disk track boundaries and
advanced built-in firmware algorithms. This paper presents a new
storage manager architecture, called Lachesis, that exploits a few
observable device-specific characteristics to achieve more robust
performance. Most notably, it enables efficiency nearly equivalent to
sequential streaming even in the presence of competing I/O traffic.
With automatic adaptation to device characteristics, Lachesis simplifies
manual configuration and restores optimizer assumptions about the
relative costs of different access patterns expressed in query plans.
Based on experiments with both IBM DB2 and an implementation inside
the Shore storage manager, Lachesis improves performance of TPC-H
queries on average by 10% when running on dedicated hardware. More
importantly, it speeds up TPC-H by up to 3X when running concurrently
with an OLTP workload, which is simultaneously improved by 7%.