In-memory column-level multi-versioned global dictionary for in-memory databases
US10726016B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 2016 |
| Grant date | Jul 28, 2020 |
| Priority date | — |
| Expiry date | Oct 16, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/3347
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques are described herein for sharing a dictionary across multiple in-memory compression units (IMCUs). After a dictionary is used to encode a first column vector in a first IMCU, the same dictionary is used to encode a second column vector in a second IMCU. The entries in the dictionary are in sort order to facilitate binary searching when performing value-to-code look-ups. If, during the encoding of the second column vector, values are encountered for which the dictionary does not already have codes, then a “sort-order-boundary” is established after the last entry in the dictionary, and entries for the newly encountered values are added to the dictionary, after the sort-order-boundary. To facilitate value-to-code look-ups, the new entries are also sorted relative to each other, creating a second “sort order set”. A new version of the dictionary may be created when the number of sort order sets in the first version of the dictionary reaches a configurable threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.