Distributed-processing database-management system

• US 20020184198A1
• Filed: 04/01/2002
• Published: 12/05/2002
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fujihara, Mutsumi, Kamimura, Shuichi
• Granted Patent: US 7,143,082 B2
• Time in Patent Office: Days
• US Class Current: 707/3
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A database-management system easy for system integration and flexible to functional modifications, etc., is provided. A database stored in each main-memory area of a plurality of computers connected via network is managed as follows: a first computer storing original data of at least a piece of data of the database is designated as a base host. At least one second computer storing replica data of the original data is designated as a replica host. A retrieving procedure is performed to receive data to be stored in a third computer from the base host storing the original data or the replica host storing the replica data in startup of the third computer, and store the received data in the main-memory of the third computer.

Claims

1. A method of managing a database stored in each main-memory area of a plurality of computers connected via network comprising:

designating a first computer storing original data of at least a piece of data of the database as a base host;

designating a second computer storing replica data of the original data as a replica host; and

performing a retrieving procedure to receive data to be stored in a third computer from the base host storing the original data or the replica host storing the replica data in startup of the third computer, and store the received data in the main-memory of the third computer.

2. The method of managing a database according to claim 2, wherein the database includes at least one lexicon set having at least one lexicon, the retrieving procedure being performed in unit of the lexicon set.

3. The method of managing a database according to claim 2, wherein the retrieving procedure is performed from the base host or the replica host already storing the data to the third computer in unit of the lexicon set, a predetermined lexicon of the lexicon set is made resident at the third computer.

4. The method of managing a database according to claim 2, further comprising:

making a list data as the original data of a system-administration lexicon set resident at a base host of the system-administration lexicon set, the list data including the lexicon set and the lexicon to be stored in each computer, a base host storing the original data of the lexicon set, and hosts to which each computer is to make a request for performing the retrieving procedure; and

transmitting the system-administration lexicon set to the third computer in startup of the third computer from the base host of the system-administration lexicon set or a replica host storing replica data of the system-administration lexicon set.

5. The method of managing a database according to claim 2, further comprising:

deciding at least one host to which a request for performing the retrieving procedure is to be made from a list data of the lexicon set and the lexicon to be stored in each computer, a base host storing original data of the lexicon set, and hosts to which each computer is to make the request, the list being registered in base host, storing a system-administration lexicon set;

determining whether there is a response from the decided host;

if no response, determining whether a computer that is making the request is the base host storing the system-administration lexicon set;

when the computer that is making the request is the base host, making resident data of the list at the computer that is making the request whereas forming a null system-administration lexicon set at the computer that is making the request if no data exists in the system-administration lexicon set.

6. The method of managing a database according to claim 4, a transcription procedure is performed to maintain uniformity between the original data at the base host and the replica data at the replica host when all data have been resident in the main-memory area of each computer, and when alteration has been made to the resident data.

7. The method of managing a database according to claim 6, wherein when a predetermined data is resident at each computer and each computer is running, further comprising:

updating data in the system-administration lexicon set at the base host; and

transmitting the updated data in the system-administration lexicon set to each computer to add data to be resident at each computer.

8. The method of managing a database according to claim 6, wherein when predetermined data is resident at each computer and each computer is running, further comprising:

requesting the base host for altering the original data of data of the system-administration lexicon set from the replica host storing the replica data of the system-administration lexicon set;

transmitting the altered data from the base host to each computer to maintain uniformity of information on data to be resident at each computer.

9. A computer readable medium containing an executable program for managing databases, the program having instructions for:

designating a first computer storing original data of at least a piece of data of a database stored in each main-memory area of a plurality of computers connected via network, as a base host;

designating a second computer storing replica data of the original data as a replica host; and

performing a retrieving procedure to receive data to be stored in a third computer from the base host storing the original data or the replica host storing the replica data in startup of the third computer, and store the received data in the main-memory of the third computer.

10. The computer readable medium containing an executable program according to claim 9, wherein the database includes at least one lexicon set having at least one lexicon, the retrieving procedure being performed in unit of the lexicon set.

11. The computer readable medium containing an executable program according to claim 10, wherein the retrieving procedure is performed from the base host or the replica host already storing the data to the third computer in unit of the lexicon set, a predetermined lexicon of the lexicon set is made resident at the third computer.

12. The computer readable medium containing an executable program according to claim 10, further having instructions:

making a list data as the original data of a system-administration lexicon set resident at a base host of the system-administration lexicon set, the list data including the lexicon set and the lexicon to be stored in each computer, a base host storing the original data of the lexicon set, and hosts to which each computer is to make a request for performing the retrieving procedure; and

transmitting the system-administration lexicon set to the third computer in startup of the third computer from the base host of the system-administration lexicon set or a replica host storing the replica data of the system-administration lexicon set.

13. The computer readable medium containing an executable program according to claim 10, further having instructions for:

deciding at least one host to which a request for performing the retrieving procedure is to be made from a list data of the lexicon set and the lexicon to be stored in each computer, a base host storing original data of the lexicon set, and hosts to which each computer is to make the request, set at each computer, the list being registered in base host, storing a system-administration lexicon set;

determining whether there is a response from the decided host;

if no response, determining whether a computer that is making the request is the base host storing the system-administration lexicon set;

when the computer that is making the request is the base host, making resident data of the list at the computer that is making the request whereas forming a null system-administration lexicon set at the computer that is making the request if no data exists in the system-administration lexicon set.

14. The computer readable medium containing an executable program according to claim 12, a transcription procedure is performed to maintain uniformity between the original data at the base host and the replica data at the replica host when all data have been resident in the main-memory area of each computer, and when alteration has been made to the resident data.

15. The computer readable medium containing an executable program according to claim 14, wherein when a predetermined data is resident at each computer and each computer is running, further having instructions for:

updating data in the system-administration lexicon set at the base host; and

transmitting the updated data in the system-administration lexicon set to each computer to add data to be resident at each computer.

16. The computer readable medium containing an executable program according to claim 14, wherein when predetermined data is resident at each computer and each computer is running, further having instructions for:

requesting the base host for altering the original data of the system-administration lexicon set from the replica host storing the replica data of the system-administration lexicon set;

transmitting the altered data from the base host to each computer to maintain uniformity of information on data to be resident at each computer.

18. The database-management system according to claim 17, wherein the database includes at least one lexicon set having at least one lexicon as a unit of data to be processed, the retrieving procedure being performed in unit of the lexicon set.

19. The database-management system according to claim 18, wherein the data resident-status setter includes:

a lexicon-set resident setter configured to set a list of at least one lexicon-set name to be accessed, at least one computer name at which the lexicon set of the data is to be resident, and a retrieving-host name to be used for making the data resident at the one computer;

a lexicon resident-plan setter configured to set the lexicon to be resident at each computer and the lexicon set; and

a lexicon resident-status setter configured to determine whether a lexicon is resident at each computer in accordance with the setting performed by the lexicon-set resident setter.

20. The database-management system according to claim 17 further including a transcription processor configured to maintain uniformity between the original data at the base host and the replica data at the replica host when all data have been resident in the main-memory area of each computer, and when alteration has been made to the resident data.

21. The database-management system according to claim 18, wherein a list of the lexicon set and the lexicon to be resident at each computer, the base host storing the original data of the lexicon set, and at least one host to which each computer makes a request for the retrieving procedure is set per computer, the set data being stored at a base host as original data of a system-administration lexicon set, in startup of each computer, the system-administration lexicon set being transmitted to each computer from the base host storing the original data of the system-administration lexicon set or a replica host storing replica data of the system-administration lexicon set.

22. The database-management system according to claim 21, wherein when predetermined data is resident at each computer and each computer is running, data in the system-administration lexicon set is updated at the base host storing the original data of the system-administration lexicon set, and the updated data in the system-administration lexicon set is transmitted by the transcription processor to each computer.

23. The database-management system according to claim 21, wherein when predetermined data is resident at each computer and each computer is running, data of the system-administration lexicon set is updated at a computer different from the base host storing the original data of the system-administration lexicon set, the updated data being transmitted to the base host storing the original data of the system-administration lexicon set by the transcription processor, the updated data being further transmitted from the base host to each computer to maintain uniformity of information on the lexicon set and lexicon to be resident at each computer.

17. A database-management system comprising at least two computers connected via a network, the computers having main-memory areas storing databases, each database having at least a piece of data, either of the computers being designated as an original site for storing the original of the data, the other computer being designated as a replica site for storing replica of the data, each computer including:

a data resident-status setter configured to set a list of at least one computer at which the data is to be resident, the base host storing the original data of the data, and at least one host to which the computer at which the data is to be resident makes a request for a retrieving procedure; and

a retrieved-data manager configured to transmit the request to the one host in accordance with the setting performed by the data-resident status setter, the data being transmitted to the computer that is making the request from the base host or the replica host by the retrieving procedure.