Conjunctive Selection Conditions in Main Memory

We consider the fundamental operation of applying a conjunction of selection conditions to a set of records. With large main memories available cheaply, systems may choose to keep the data entirely in main memory, in order to improve query and/or update performance. The design of a data-intensive algorithm in main memory needs to take into account the architectural characteristics of modern processors, just as a disk-based method needs to consider the physical characteristics of disk devices. An important architectural feature that influences the performance of main memory algorithms is the branch misprediction penalty. We demonstrate that branch misprediction has a substantial impact on the performance of an algorithm for applying selection conditions. We describe a space of "query plans" that are logically equivalent, but differ in terms of performance due to variations in their branch prediction behavior. We propose a cost model that takes branch prediction into account, ...

• Type: Conference
• Year: 2002
• Where: PODS
• Authors: Kenneth A. Ross
• Keywords: Branch Prediction Behavior, Database, Heuristic Optimization Algorithm, PODS 2002, Query Optimization Algorithm