Method and system for controlling accesses to a database

• US 20090193025A1
• Filed: 12/05/2008
• Published: 07/30/2009
• Est. Priority Date: 12/07/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Iwamoto, Yuhko
• Granted Patent: US 8,176,076 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2471 Distributed queries

Abstract

The frequency of occurrences of an exclusion process is reduced so as to enhance the efficiency of handling accesses to a database. A system is provided for controlling accesses to a database. The system includes a database identifying section that identifies a database corresponding to an input of a first access command, an access judging section that judges whether a series of accesses to the identified database initiated by a second access command still continue, a frequency determining section that determines how often accesses to the identified database occur with reference to a history of accesses. The system further comprises an access control section that checks the accesses made by the first access command to the identified database when the series of accesses to the identified database initiated by the second access command still continue and the frequency of accesses to the identified database determined by the frequency determining section is higher than or equal to a predetermined value.

Claims

1. A system for controlling accesses to a database, comprising:

a database identifying section that identifies a database corresponding to an input of a first access command;

an access judging section that determines whether a series of accesses to the identified database initiated by a second access command still continue;

a frequency determining section that determines how often accesses to the identified database occur with reference to a history of accesses; and

an access control section that checks the access made by the first access command to the identified database, under the condition that the series of accesses to the identified database initiated by the second access command still continue and the frequency of accesses to the identified database determined by the frequency determining section is higher than or equal to a predetermined value.

2. The system of claim 1, further comprising an arbitrating section that excludes two or more competing accesses made by a plurality of access commands to a single database, wherein

the access control section controls the access to the identified database made by the first access command to reduce a frequency at which the arbitrating section performs the exclusion of the two or more competing accesses for the identified database.

3. The system of claim 2, wherein the first access command initiates a first batch process, and

the second access command initiates a second batch process which executes the series of accesses to the identified database.

4. The system of claim 3, wherein upon checking the access made by the first access command, the access control section suspends the first batch process to be executed and commits one or more processes of the first batch process which have already been executed.

5. The system of claim 2, wherein the access judging section determines whether a first computer which issues the first access command is different from a second computer which issues the second access command, and

the access control section blocks the access to the identified database made by the first access command, under the condition that the first computer is different from the second computer.

6. The system of claim 2, wherein the access judging section determines whether the series of accesses initiated by the second access command update the identified database, and

the access control section blocks the access to the identified database made by the first access command, under the condition that the series of accesses initiated by the second access command update the identified database.

7. The system of claim 2, wherein the access judging section determines whether the series of accesses initiated by the second access command create a new record in the identified database, and

the access control section blocks the access to the identified database made by the first access command, under the condition that the series of accesses made by the second access command create a new record in the identified database.

8. The system of claim 2, wherein the frequency determining section determines a frequency of accesses to the identified database for each of the series of accesses to the identified database which have been committed, and

the access control section blocks the access to the identified database made by the first access command, under the condition that the highest frequency is higher than or equal to the predetermined value.

9. The system of claim 2, wherein under the condition that more than one series of accesses to the identified database have been committed, the frequency determining section determines a frequency of the most recently committed series of accesses.

10. The system of claim 2, wherein the system manages a storage control information recording therein information, for identifying a computer which issues an access command, information for identifying a database accessed by the access command, a type of accesses designated by the access command, an access start time, a commit time and the number of the accesses, in association with one another,

wherein the system further comprises a storage section that, under the condition that the access control section permits starting an access to a database made by an access command, stores (i) information for identifying a computer which issues the access command, (ii) information for identifying the database for the access, (iii) a type of the access designated by the access command, and (iv) an access start time, into the control information the system manages in a storage device,

at each time of committing a process initiated by the access command, the storage section updates a commit time and the number of accesses in a record associated with the access command in the control information in the storage device,

the access judging section reads, from the control information in the storage device, a record associated with the identified database, and determining that the series of accesses to the identified database made by the second access command continue under the condition that no commit time is recorded in the record read by the access judging section, and

the frequency determining section reads, from the control information in the storage device, the record associated with the identified database, and determines the frequency of accesses to the identified database based on an access start time, a commit time and the number of accesses in the record read by the frequency determining section.

11. The system of claim 2, further comprising a reference value calculating section that sequentially monitors an available process capacity per unit time of the arbitrating section, and sequentially obtains a reference value by dividing the available process capacity by a predetermined process capacity required to perform one cycle of the exclusion process, wherein

the arbitrating section blocks access under the condition that the frequency of accesses is higher than or equal to the reference value calculated by the reference value calculating section.

12. A computer program product having computer instructions recorded on a computer readable medium, for enabling a computer executing the computer instructions to perform operations comprising:

identifying a database corresponding to an input of a first access command;

determining whether a series of accesses to the identified database, initiated by a second access command still continue;

determining how often accesses to the identified database occur with reference to a history of accesses; and

checking the access made by the first access command to the identified database under the condition that the series of accesses to the identified database initiated by the second access command still continue and the frequency of accesses to the identified database determined by the frequency section is higher than or equal to a predetermined value.

13. The program product of claim 12, further comprising excluding two or more competing accesses made by a plurality of access commands to a single database, wherein

controlling the access to the identified database made by the first access command to reduce a frequency at which the arbitrating section performs the exclusion process for the identified database.

14. The program product of claim 12, wherein

the first accessing command initiates a first batch process, and

the second accessing command initiates a second batch process which executes the series of accesses to the identified database.

15. The program product of claim 12,

further comprising determining whether the series of accesses initiated by the second access command update the identified database, and

blocking access to the identified database made by the first access command, under the condition that the series of accesses initiated by the second access command update the identified database.

16. The program product of claim 12,

further comprising determining a frequency of accesses to the identified database for each of the series of accesses to the identified database which have been committed, and

blocking the access to the identified database made by the first access command, under the condition that the highest frequency is higher than or equal to the predetermined value.

17. The program product of claim 12, further comprising managing a storage control information, recording therein information for identifying a computer which issues access commands, information for identifying a database accessed by the accessing commands, information for identifying a type of accesses designated by the access command, an access start time, a commit time and the number of the accesses, in association with one another,

wherein the program product further comprises a storage section that, under the condition that the access control section permits starting an access to a database made by an access command, stores (i) information for identifying a computer which issues the access command, (ii) information for identifying the database for the access, (iii) a type of the access designated by the access command, and (iv) an access start time, into the control information the program product manages in the storage device,

at each time of committing a process initiated by the access command, the storage section updates a commit time and the number of accesses in a record associated with the access command in the control information in a storage device,

the access judging section reads, from the control information in the storage device, a record associated with the identified database, and determines the series of accesses to the identified database made by the second access command continue under the condition that no commit time is recorded in the record and read by the access judging section, and

the frequency determining section reads, from the control information in the storage device, the record associated with the identified database, and determines the frequency of accesses to the identified database based on an access start time, a commit time and the number of accesses in the record read by the frequency determining section.

18. A computing system comprising a processor coupled to a computer-readable memory unit, said memory unit comprising a software application, said software application comprising instructions that when executed by said processor implement the system comprising:

a database identifying section that identifies a database corresponding to an input of a first access command;

an access judging section that determines whether a series of accesses to the identified database initiated by a second access command still continue;

a frequency determining section that determines how often accesses to the identified database occurs with reference to a history of accesses; and

an access control section that checks the access made by the first access command to the identified database, under the condition that the series of accesses to the identified database initiated by the second access command still continue and the frequency of accesses to the identified database determined by the frequency determining section is higher than or equal to a predetermined value.

19. A method for controlling accesses to a database, comprising:

identifying a database by an input of a first access command;

determining whether a series of accesses to the identified database initiated by a second access command still continue;

determining how often accesses to the identified database occurs with reference to a history of accesses; and

checking the access made by the first access command to the identified database under the condition that the series of accesses to the identified database initiated by the second access command still continue and the frequency of accesses to the identified database determined by the frequency determining section is higher than or equal to a predetermined value.

20. A system for controlling accesses to a database, comprising:

An arbitrating section that excludes one or more competing accesses made by a plurality of access commands to a same database;

a database identifying section that identifies a database corresponding to an input of a first access command;

an access judging section that determines whether a series of accesses to the identified database initiated by a second access command still continue; and

an access control section that checks the access made by the first access command to the identified database under the condition that the series of accesses to the identified database initiated by the second access command still continue.