US4881166A
Expired / Lapsed
US
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Method for consistent multidatabase transaction processing
Assignee: BP Corp North America Inc
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Filing: 1987-07-24
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Granted: 1989-11-14
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Expires: 2007-07-24
Abstract
Abstract Disclosed is a concurrency control method and related system for permitting the correct execution of multiple concurrent transactions, each comprising one or more read and/or write operations, in a heterogeneous distributed database system. Read and write operations are processed at the required sites if no site cycles are detected. If any site cycles are detected in a read operation, then new sites are searched for. If any site cycle is detected for any of the sites for a write operation, then the transaction is aborted.
Inventors
- 👤 Glenn R. Thompson
- 👤 Yuri J. Breitbart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:17
CPC Classifications
G; G06; G06F; G06F16/00; G06F16/20; G06F16/25; G06F16/23; G06F16/2308; G06F16/2336; Y; Y10; Y10S; Y10S707/00; Y10S707/99931; Y10S707/99938; Y10S707/99939
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
191 words
A concurrency control method for permitting the correct execution of multiple concurrent transactions, each comprising one or more read and/or write operations, in a distributed heterogeneous database system, comprising: (a) upon receipt of a read operation request, identifying the sites in the system that contain data needed for the read operation; (b) determining if the transaction including the read operation request has processed a previous operation at any of the identified sites; (c) for the condition of step (b) where a previous operation has been processed, perform the read operation; (d) for the condition of step (b) where a previous operation has not been processed, select a site from the identified sites and determine if a site cycle occurs at the selected site; (e) for the condition of step (d) where a site cycle occurs, select another site from the selected sites and redo step (d); (f) for the condition of step (d) where no site cycle occurs at one of the sites, perform the read operation at that selected site; and (g) for the condition of step (d) where a site cycle occurs for all selected sites, cancel the transaction.
Claim 2
Dependent Claim
191 words
A concurrency control method for permitting the correct execution of multiple concurrent transactions, each comprising one or more read and/or write operations, in a distributed heterogeneous database system, comprising: (a) upon receipt of a read operation request, identifying the sites in the system that contain data needed for the read operation; (b) determining if the transaction including the read operation request has processed a previous operation at any of the identified sites; (c) for the condition of step (b) where a previous operation has been processed, perform the read operation; (d) for the condition of step (b) where a previous operation has not been processed, select a site from the identified sites and determine if a site cycle occurs at the selected site; (e) for the condition of step (d) where a site cycle occurs, select another site from the selected sites and redo step (d); (f) for the condition of step (d) where no site cycle occurs at one of the sites, perform the read operation at that selected site; and (g) for the condition of step (d) where a site cycle occurs for all selected sites, cancel the transaction.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein step (a) further comprises accessing a data location directory within the system, and selecting the sites from the directory where needed data resides.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein step (b) further comprises determining if a server has previously been allocated to a particular selected site for a transaction.
Claim 5
Dependent Claim
56 words
The method of claim 1 wherein the performance of the read operation in step (c) further comprises, using a server, translating a request for data into the language of a selected local database management system, providing the value of the data to the server, and providing the data value to the MDBS system from the server.
Claim 6
Dependent Claim
34 words
The method of claim 1 wherein the step of determining if a site cycle occurs comprises processing a labeled undirected site graph to determine if more than one path exists between any two sites.
Claim 7
Dependent Claim
111 words
A concurrency control method for permitting the correct execution of multiple concurrent transactions, each comprising one or more read and/or write operations, in a heterogeneous distributed database system, comprising: (a) upon receipt of a write operation request, identifying the sites that contain data needed for the write operation; (b) determining if a site cycle occurs at any of the sites identified in step (a); (c) for the condition of steps (b) where no site cycle occurs for any of the sites, perform the write operation at each of the sites; and (d) for the condition of step (b) where at least one site cycle occurs for the sites, cancel the transaction.
Claim 8
Dependent Claim
111 words
A concurrency control method for permitting the correct execution of multiple concurrent transactions, each comprising one or more read and/or write operations, in a heterogeneous distributed database system, comprising: (a) upon receipt of a write operation request, identifying the sites that contain data needed for the write operation; (b) determining if a site cycle occurs at any of the sites identified in step (a); (c) for the condition of steps (b) where no site cycle occurs for any of the sites, perform the write operation at each of the sites; and (d) for the condition of step (b) where at least one site cycle occurs for the sites, cancel the transaction.
Claim 9
Dependent Claim
29 words
The method of claim 6 wherein step (a) further comprises accessing a data location directory within the system, and determining the sites from the directory where needed data resides.
Claim 10
Dependent Claim
28 words
The method of claim 6 wherein step (b) further comprises processing a labeled undirected site graph to determine if more than one path exists between any two sites.
Claim 11
Dependent Claim
62 words
The method of claim 6 wherein the write operation comprises using servers translating the write request into the language of the selected local database management systems, each at a selected site; having each server provide the specified data value to the local database management system; and having each local database management system replace a previous data value with the specified data value.
Claim 12
Dependent Claim
90 words
A concurrency control system for permitting the correct execution of multiple concurrent transactions, each transaction comprising one or more read and/or write operations, in a heterogeneous distributed database system, comprising: (a) means for identifying the sites that contain data needed for a read operation; (b) means for determining if the transaction containing the read operation request has processed a previous operation at any of the identified sites; (c) means for performing the read operation; and (d) means for determining if a site cycle occurs for any of the selected sites.
Claim 13
Dependent Claim
90 words
A concurrency control system for permitting the correct execution of multiple concurrent transactions, each transaction comprising one or more read and/or write operations, in a heterogeneous distributed database system, comprising: (a) means for identifying the sites that contain data needed for a read operation; (b) means for determining if the transaction containing the read operation request has processed a previous operation at any of the identified sites; (c) means for performing the read operation; and (d) means for determining if a site cycle occurs for any of the selected sites.
Claim 14
Dependent Claim
72 words
A concurrency control system for permitting the correct execution of multiple concurrent transactions, each comprising one or more read and/or write operations, in a heterogeneous distributed database system, comprising: (a) means for identifying the sites that contain data needed for a write operation; (b) means for determining if a site cycle occurs for any of the sites identified; and (c) means for performing the write operation at each of the identified sites.
Claim 15
Dependent Claim
72 words
A concurrency control system for permitting the correct execution of multiple concurrent transactions, each comprising one or more read and/or write operations, in a heterogeneous distributed database system, comprising: (a) means for identifying the sites that contain data needed for a write operation; (b) means for determining if a site cycle occurs for any of the sites identified; and (c) means for performing the write operation at each of the identified sites.
References Cited (Backward Citations)
US4627019A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |