On-demand hash index
US9262457B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 2013 |
| Grant date | Feb 16, 2016 |
| Priority date | — |
| Expiry date | Apr 8, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/2255
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Disclosed herein are system, method, and computer program product embodiments for populating a hash index and returning a handle to the hash index. An embodiment operates by determining, by at least one processor, during query optimization that a first database query has a query execution plan comprising a sub-query which executes N times a correlated predicate having an operator being one of equal and not equal to a base column. A cost of creating and probing the hash index N times and a cost of fully scanning the base column N times are compared based on the correlated predicate. Based on the comparing, it is determined whether to create on-demand a hash index.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.