Generalized method for modeling complex ordered check constraints in a relational database system
US7328212B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2001 |
| Grant date | Feb 5, 2008 |
| Priority date | — |
| Expiry date | Oct 13, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99937
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for enabling a user of a relational database to define and enforce ordered check constraints to insure that defined logical relationships are maintained between data values in pairs of adjacent rows when adjacency is defined by some ordering of the data. These inter-row conditions, here called “ordered check constraints,” are expressed by a logical expressions which define a required relationship between the attributes of a given row and its adjacent row or rows. Arbitrarily complex expressions involving these sets of attributes can be formed to model the constraints of interest. These expressions can be created by the database in support of, for example, traditional primary key or uniqueness constraints, or they can be provided by the database user to model new more complex constraints such as a requirement that there be no gaps in a list of serial numbers. These constraints can then be efficiently supported in the presence of a b-tree or another ordered index structure by identifying any inserted, updated or deleted rows and evaluating the expression in the context of those rows and any associated adjacent rows. This approach is similar to that typically used in existing…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.