Processing of deterministic user-defined functions using multiple corresponding hash tables
US7890480B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 2008 |
| Grant date | Feb 15, 2011 |
| Priority date | — |
| Expiry date | Mar 12, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/2255
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A deterministic UDF processing mechanism processes user-defined functions (UDFs) using multiple hash tables. Data access patterns for a UDF are collected, and an appropriate hash table set is then determined for the UDF from the data access patterns. If a UDF accesses some similar columns and some disjoint columns, the similar columns are grouped together, and one or more hash tables are allocated to the similar columns. Disjoint columns are allocated their own hash tables. In addition, the allocation of hash tables may be adjusted based on historical access patterns collected over time. By dynamically allocating and adjusting sets of hash tables to a deterministic UDF, the performance of the UDF is greatly increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.