Method and system for querying database, as well as a recording medium for storing a database querying program

• US 20010051939A1
• Filed: 03/26/2001
• Published: 12/13/2001
• Est. Priority Date: 06/12/2000
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nishikawa, Norifumi, Yagawa, Yuichi, Hayashi, Shigetoshi, Yoshimura, Mitsuhiko, Inaba, Keiichiro
• Granted Patent: US 6,882,994 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2322 using timestamps
• CPC Class Codes: G06F 16/2358 Change logging, detection, and notification replication G06F16/27
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99936 Pattern matching access
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

The present invention provides techniques for answering a user'"'"'s query to a database system. An embodiment provides a database querying method in which a first data item is obtained from a Data Base Management System (DBMS) database table in response to a query request. A second data item is obtained by referencing a DBMS updated log file, having log data associated with the first data item, for example a timestamp. The first and second data items are then integrated and returned as an integration result to the query request. In one embodiment the first and second data items are integrated in a virtual table in accordance with a predetermined business rule.

Claims

1. A database querying method, comprising:

obtaining a first data item from a database table of a database system in response to a query request;

obtaining a second data item based on a value related to said first data item, said value in an updated log file of said database system;

integrating said first and second data items into an integration result; and

returning said integration result to said query request.

2. The database querying method of

claim 1

,

wherein said second data item is obtained by translating said value according to a predetermined translation rule.

3. A database querying system comprising:

a database access module for obtaining a first data item from a database table of a database system in response to a query request;

a log extractor module for obtaining a second data item based on a value related to said first data item, said value in an updated log file of said database system; and

an integrator module for integrating said first and second data items into an integration result, said integration result related to a response to said query request.

4. The database querying system of

claim 3

further comprising:

a translator module coupled with said log extractor module and with said integrator module for modifying said second data item from said log extractor module according to a predetermined translation rule, before said second data item is used by said integrator module.

5. A database querying system, comprising:

a database processor for receiving a query request and returning a requested record set in response to the query request; and

a database system comprising a database table and an updated log file;

wherein said database processor is operably disposed to;

retrieving a first item from said database table responsive to said query request;

retrieving a second item, comprising updated log data corresponding to said first item, from said updated log file;

generating said requested record set, comprising said first item and said second item; and

returning said requested record set to a query request origin.

6. The database querying system according to

claim 5

,

wherein the database processor comprises a translator for translating updated log data, according to a predetermined translation rule, into translated log data and substituting said translated log data for said updated log data in said second item.

7. A computer program product for use with a database system, comprising:

a computer readable medium having program code embodied in said computer readable medium, said program code comprising;

program code for obtaining a first data item from a database table of said database system in response to a query request;

program code for obtaining a second data item based on a value related to said first data item, said value in an updated log file of said database system;

program code for integrating said first and second data items into an integration result; and

program code for returning said integration result to said query request.

8. A database question and answer method using one or more databases, each database comprising a database table and an updated log file, said updated log file comprising information associated with said database table, said method comprising:

receiving a query request from a user, said query request comprising a first data item of said database table;

using said first data item, obtaining a second data item from said updated log file;

modifying said second data item to a third data item using a predetermined business rule;

generating a virtual table comprising said first and third data items; and

returning to said user an answer based on said virtual table.

9. The database question and answer method of

claim 8

wherein said virtual table is discarded after said answer is returned to said user.

10. The database question and answer method of

claim 8

wherein said predetermined business rule comprises an accounting time period.

11. The database question and answer method of

claim 10

wherein the accounting time period is a fixed day in a month.

12. The database question and answer method of

claim 8

wherein said predetermined business rule comprises a base time period.

13. The database question and answer method of

claim 8

wherein said predetermined business rule comprises a selected national calendar format for the day, month, and year.

14. The database question and answer method of

claim 8

, wherein said selected national calendar format is selected from a group consisting of a Japanese Calendar or a U.S. Calendar.

15. The database question and answer method of

claim 8

wherein said predetermined business rule comprises a table name.

16. The database question and answer method of

claim 8

further comprising:

when said query request is for a plurality of databases, dividing said query request into a plurality of sub-requests, each sub-request directed to a database of said plurality of databases;

receiving a record set of a plurality of record sets in response to said sub-request; and

integrating said plurality of record sets into a result for returning to said user.

17. The database question and answer method of

claim 8

wherein said second data item comprises a timestamp for said first data item.

18. The database question and answer method of

claim 8

wherein said virtual table is a view table.

19. The database question and answer method of

claim 8

wherein said request is based on a search of said information in said updated log file.

20. A system for responding to a user query to a data base management systems (DBMS), wherein said DBMS comprises a database table and an updated log file, said system comprising:

a database access controller for retrieving a data item from said database table responsive to said user query;

a translation module coupled with said database access controller for retrieving an attribute related to said data item from said updated log file and for translating said attribute into a modified attribute according to a translation rule; and

an integrator module for integrating said data item and said modified attribute into a virtual table and returning to said user query an answer based on said virtual table.

21. The system of

claim 20

wherein said attribute is a timestamp.

22. The system of

claim 20

wherein said translation rule comprises a base time period.

23. The system of

claim 20

wherein said translation rule comprises a predetermined country'"'"'s calendar format.

24. A system for responding to a user query to a data base management systems (DBMS), wherein said DBMS comprises a database table and an updated log file, said system comprising:

an access means for retrieving a data item from said database table responsive to said user query;

an extraction means for retrieving an attribute related to said data item from said updated log file;

a translation means for translating said attribute into a modified attribute according to a translation rule; and

a virtual table comprising said data item and said modified attribute wherein a response to said user query is based on said virtual table.

25. A computer readable data transmission medium containing a data structure for responding to a user query, comprising:

a first part, comprising a database table entry, responsive to said user query; and

a second part, comprising, a timestamp modified by a translation rule, wherein said timestamp is a time value in an updated log file associated with said database table entry.

26. The computer readable data transmission medium of

claim 25

wherein said data structure is a virtual table.

27. A computer readable medium for storing code for querying a database querying, comprising:

code for obtaining a first data item from a database table of a database system in response to a query request;

code for obtaining a second data item based on a value related to said first data item, said value in an updated log file of said database system;

code for integrating said first and second data items into an integration result; and

code for returning said integration result to said query request.

28. The computer readable medium of

claim 27

, further comprising code for obtaining said second data item by translating said value according to a predetermined translation rule.

29. A database querying system comprising:

an access means for obtaining a first data item from a database table of a database system in response to a query request;

an extractor means for obtaining a second data item based on a value related to said first data item, said value in an updated log file of said database system; and

an integrator means for integrating said first and second data items into an integration result, said integration result related to a response to said query request.

30. The database querying system of

claim 29

further comprising:

a translator means for modifying said second data item from said log extractor module according to a predetermined translation rule, before said second data item is used by said integrator module.