Conversion of queries to monotonically increasing incremental form to continuously query a append only database
US5495600A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1992 |
| Grant date | Feb 27, 1996 |
| Priority date | — |
| Expiry date | Jun 3, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99933
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
To produce a continuous query for an append-only database, a client defined query first is converted into its minimal bounding non-decreasing monotone (hereinafter referred to as "monotonic increasing" query. This monotonic query, in turn, is converted into an incremental query, The resulting monotonically increasing incremental query then is installed on the database as a stored procedure that takes two date/time parameters (hereinafter referred to as "time" parameters), one of which (.tau.) identifies the last time the procedure was executed, and the other of which (t) identifies the current time. All database records are timestamped as of the time that they are entered into the database. Thus, in operation, more or less standard procedure calls periodically invoke each of the stored query procedures, thereby periodically executing the incremental queries over database records that have timestamps spanning successive time slots.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.