Adaptive aggregation: improving the performance of grouping and duplicate elimination by avoiding unnecessary disk access
US8352470B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2008 |
| Grant date | Jan 8, 2013 |
| Priority date | — |
| Expiry date | Dec 3, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/244
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for use with an aggregation operation (e.g., on a relational database table) includes a sorting pass and a merging pass. The sorting pass includes: (a) reading blocks of the table from a storage medium into a memory using an aggregation method until the memory is substantially full or until all the data have been read into the memory; (b) determining a number k of blocks to write back to the storage medium from the memory; (c) selecting k blocks from memory, sorting the k blocks, and then writing the k blocks back to the storage medium as a new sublist; and (d) repeating steps (a), (b), and (c) for any unprocessed tuples in the database table. The merging pass includes: merging all the sublists to form an aggregation result using a merge-sort algorithm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.