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Patent US5222233A successfully refreshed from Google Patents.
US5222233A
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Method for restructuring a database using a relational database scheme derived by selecting subscheme joins to avoid cycles
Assignee: United States Department of the Navy
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Filing: 1990-07-09
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Granted: 1993-06-22
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Expires: 2010-07-09
Abstract
Abstract A method for relational database scheme design with the aid of a digital puter for a database having attributes A i , i=1 to n and relational schemes R j , j=1 to m. Each relational scheme R j is a non-empty subset of the attributes A i . The method detects any scheme that is non-acyclic in a simple manner that is easily adapted to a digital computer environment. The resulting relational database scheme design is thereby prevented from being non-acyclic.
Inventors
- 👤 Allen D. Parks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:00
CPC Classifications
G; G06; G06F; G06F16/00; G06F16/20; G06F16/28; G06F16/284; Y; Y10; Y10S; Y10S707/00; Y10S707/953; Y10S707/954; Y10S707/99941; Y10S707/99943
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
172 words
A method for dynamically generating, with the aid of a digital computer, a relational database scheme that is prevented from being overtly non-acyclic in a homological sense, comprising the steps of: a) providing said computer with a database having attributes A i , i=1 to n, and relational schemes R j , j=1 to m, each relational scheme R j comprising an acyclic, non-empty subset of said attributes A i ; b) selecting a first relational scheme R 1 as a base relational database scheme S; c) initializing j to 1; d) selecting another relational scheme R j+1 ; e) determining a scheme acyclicity condition of a union (S ∪ R j+1 ) between said base scheme S and said another relational scheme R j+1 ; f) selectively updating said base scheme S to include the relational database scheme R j+1 when said union's scheme acyclicity condition is not indicative of an overtly non-acyclic database scheme; g) incrementing j by 1; and h) repeating steps d) through g) for j=2 to m-1.
Claim 2
Independent Claim
172 words
A method for dynamically generating, with the aid of a digital computer, a relational database scheme that is prevented from being overtly non-acyclic in a homological sense, comprising the steps of: a) providing said computer with a database having attributes A i , i=1 to n, and relational schemes R j , j=1 to m, each relational scheme R j comprising an acyclic, non-empty subset of said attributes A i ; b) selecting a first relational scheme R 1 as a base relational database scheme S; c) initializing j to 1; d) selecting another relational scheme R j+1 ; e) determining a scheme acyclicity condition of a union (S ∪ R j+1 ) between said base scheme S and said another relational scheme R j+1 ; f) selectively updating said base scheme S to include the relational database scheme R j+1 when said union's scheme acyclicity condition is not indicative of an overtly non-acyclic database scheme; g) incrementing j by 1; and h) repeating steps d) through g) for j=2 to m-1.
Claim 3
Dependent Claim
126 words
A method according to claim 1, each relational scheme R j being a single relational scheme wherein, for each non-empty subset of said union, each non-empty subset having from 1 to k max attributes contained therein, said step of determining comprises the steps of: a) generating a set a k , k=1 to k max , from said union, wherein each set member a k has a value indicating the number of subsets within said union having k attributes; and b) calculating in said computer an equation ##EQU5## wherein each relational scheme R j is connected with all relational schemes R y , y=1 to m and y≠j, and wherein said union is overtly non-acyclic when the result of said equation is not equal to one.
Claim 4
Dependent Claim
35 words
A method according to claim 2 wherein said union further comprises p non-connected groups of connected subsets, and wherein said union is overtly non-acyclic when the result of said equation is not equal to p.
Claim 5
Independent Claim
203 words
A method for dynamically adjoining, with the aid of a digital computer, relational database schemes into a unified database scheme that is prevented from being overtly non-acyclic in a homological sense, comprising the steps of: a) providing said computer with a plurality of database schemes S h , h=1 to L, having attributes A i and relational schemes R j , each relational scheme R j comprising an acyclic, non-empty subset of said attributes A i ; b) selecting a first database scheme S 1 as a base scheme S; c) initializing h to 1; d) selecting another database scheme S h+1 , wherein an intersection (S ∩ S h+1 ) between said base scheme S and said another database scheme S h+1 is non-empty; e) determining a scheme acyclicity condition of a union (S ∪ S h+1 ) between said base scheme S and said another database scheme S h+1 ; f) selectively updating said base scheme S to include the database scheme S h+1 when said union's scheme acyclicity condition is not indicative of an overtly non-acyclic database scheme; g) incrementing h by 1; and h) repeating steps d) through g) for h=2 to L-1 to generate the unified database scheme.
Claim 6
Independent Claim
203 words
A method for dynamically adjoining, with the aid of a digital computer, relational database schemes into a unified database scheme that is prevented from being overtly non-acyclic in a homological sense, comprising the steps of: a) providing said computer with a plurality of database schemes S h , h=1 to L, having attributes A i and relational schemes R j , each relational scheme R j comprising an acyclic, non-empty subset of said attributes A i ; b) selecting a first database scheme S 1 as a base scheme S; c) initializing h to 1; d) selecting another database scheme S h+1 , wherein an intersection (S ∩ S h+1 ) between said base scheme S and said another database scheme S h+1 is non-empty; e) determining a scheme acyclicity condition of a union (S ∪ S h+1 ) between said base scheme S and said another database scheme S h+1 ; f) selectively updating said base scheme S to include the database scheme S h+1 when said union's scheme acyclicity condition is not indicative of an overtly non-acyclic database scheme; g) incrementing h by 1; and h) repeating steps d) through g) for h=2 to L-1 to generate the unified database scheme.
Claim 7
Dependent Claim
126 words
A method according to claim 4, each relational scheme R j being a single relational scheme wherein, for each non-empty subset of said union, each non-empty subset having from 1 to k max attributes contained therein, said step of determining comprises the steps of: a) generating a set a k , k=1 to k max , from said union, wherein each set member a k has a value indicating the number of subsets within said union having k attributes; and b) calculating in said computer an equation ##EQU6## wherein each database scheme S h is connected with all database schemes S y , y=1 to L and y≠L, and wherein said union is overtly non-acyclic when a result of said equation is not equal to one.
Claim 8
Dependent Claim
35 words
A method according to claim 5 wherein said union further comprises p non-connected groups of connected subsets, and wherein said union is overtly non-acyclic when the result of said equation is not equal to p.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |