Generic Database Cost Models for Hierarchical Memory Systems
Accurate prediction of operator execution time is a prerequisite for database query optimization. Although extensively studied for conventional disk-based DBMSs, cost modeling in main-memory DBMSs is still an open issue. Recent database research has demonstrated that memory access is more and more becoming a significant - if not the major - cost component of database operations. If used properly, fast but small cache memories - usually organized in cascading hierarchy between CPU and main memory - can help to reduce memory access costs. However, they make the cost estimation problem more complex.