Compact aggregation working areas for efficient grouping and aggregation using multi-core CPUs

摘要

A system is described for creating compact aggregation working areas for efficient grouping and aggregation using multi-core CPUs. The system implements operations including computing a running aggregate for a group within a business intelligence (BI) query, and identifying a location to store running aggregate information within an aggregation working area of a cache. The aggregation working area includes first and second data structures. The first data structure stores running aggregate information that is associated with a group that is accessed frequently relative to a threshold. The second data structure stores running aggregate information that is associated with a group that is accessed infrequently relative to the threshold. The operations also include storing the running aggregate information in either the first or second data structure of the aggregation working area based on a characterization of the group as a frequently or infrequently accessed group.

主权项

1. A computer program product comprising a non-transitory computer useable storage medium to store a computer readable program, wherein the computer readable program, when executed on a computer, causes the computer to perform operations comprising:
computing a running aggregate for a group within a business intelligence (BI) query; identifying a location to store running aggregate information within an aggregation working area of a cache, wherein the aggregation working area comprises:
a first data structure for storing running aggregate information that is associated with a group that is accessed frequently relative to a threshold; anda second data structure for storing running aggregate information that is associated with a group that is accessed infrequently relative to the threshold; estimating a final value of the running aggregate; estimating a number of bits for storing the final value of the running aggregate; allocating the estimated number of bits within either the first or second data structure; and storing the running aggregate information in either the first or second data structure of the aggregation working area based on a characterization of the group as a frequently or infrequently accessed group.