Method and means for linking a database system with a system for filing data

• US 6,029,160 A
• Filed: 08/15/1997
• Issued: 02/22/2000
• Est. Priority Date: 05/24/1995
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cabrera, Luis Felipe, Rees, Robert Michael, Narang, Inderpal Singh
• Primary Examiner(s): Kulik, Paul V.
• Assistant Examiner(s): Coby, Frantz
• Application Number:
  US08/921,770
• Time in Patent Office: 921 Days
• Field of Search: 707/1, 707/100, 707/104, 707/102, 707/10, 395/200.31, 395/200.33
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/28 Databases characterised by their database models, e.g. relational or object models
• CPC Class Codes: G06F 21/6227 where protection concerns the structure of data, e.g. records, types, queries
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

Extensions to a database system provide linkage between data in the database system and files in a system for filing data which is external to the database system ("the filing system"). The linkage includes an external file reference (efr) data type which is defined in the database system for reference to files that are stored in the filing system. When entries are made in the database system that include efr data-type references to files in the filing system, control information is provided by the database system to the filing system. The control information causes the filing system to control processing of referenced files according to referential constraints established in the database system.

Claims

1. A method for accessing file objects from a client application using a database system, the file objects being stored in a system for filing data (filing system), the method comprising the steps of:

creating a connection between the database system and the filing system for exchange of information between the database system and the filing system respecting file objects in the filing system;

defining a data type in the database system for reference to file objects in the filing system (EFR data type);

entering data into the database system which includes an EFR data type field that contains a reference to a file object in the filing system; and

providing control information on the connection between the database system and the filing system which causes the filing system to control processing of the file object according to referential integrity constraints established at the database system.

2. The method of claim 1, wherein the client application includes a first interface with the database system and a second interface with the filing system, further including the steps of:

providing a request from the client application to the database system through the first interface for retrieval of an entry which includes a reference to the file object;

providing a response from the database system through the first interface that includes the reference to the file object; and

obtaining the file object from the filing system through the second interface using the reference.

3. The method of claim 2, further including the step of:

prior to the step of obtaining, providing a request from the client application through the second interface for access to the file object, the request including the reference to the file object.

4. The method of claim 3, wherein:

the step of providing a response from the database system includes generating a token denoting access authorization of the database system to file objects in the filing system, and appending the token to the reference, the response including the reference and appended token;

in the step of providing a request from the client application through the second interface, the request includes the reference and appended token; and

the step of obtaining the file object is preceded by the step of authorizing access to the file by the client application in response to the token.

5. The method of claim 1, further including the following steps, performed in the filing system:

receiving a request from a user of the filing system to rename or delete the file object; and

rejecting the request in response to the control information.

6. The method of claim 1, further including the steps of:

defining a relation over the EFR data type, the relation being represented by a table including a column defined over the EFR data type; and

providing a group identification on the connection between the database system and the filing system, the group identification for identifying any file object referenced in the column.

7. The method of claim 6, wherein the step of entering data includes entering a plurality of tuples in the table, each tuple including EFR data in a field of the column which references a file object in the filing system, and the step of providing control information includes providing identification of each file object referenced in the column, each identification including the group identification.

8. The method of claim 7, further including the steps of:

deleting the relation from the database system;

followed by,

returning control of file objects referenced in the column to the filing system by deleting the referential integrity constraints for the file objects at the filing system in response to a request from the database system;

or

deleting file objects referenced in the column from the filing system in response to a request from the database system.

9. The method of claim 8, further including:

deleting the data from the database system;

followed by

returning control of the file object referenced in the EFR data type field to the filing system by deleting the referential integrity constraints with respect to the file object at the filing system in response to a request from the database system;

or

deleting the file object referenced in the EFR data type field from the filing system in response to a request from the database system.

10. The method of claim 1, further including:

deleting the data from the database system;

followed by

returning control of the file object referenced in the EFR data type field to the filing system by deleting the referential integrity constraints with respect to the file object at the filing system in response to a request from the database system;

or

deleting the file object referenced in the EFR data type field from the filing system in response to a request from the database system.

22. The method of claim 1, wherein the file objects are files.

23. The method of claim 1, wherein the file objects are bit files.

11. A combination for accessing file objects from a client application using a database system, the file objects being stored in a system for filing data (filing system), the combination comprising:

means for creating a connection between the database system and the filing system;

means for defining a data type in the database system for reference to file objects in the filing system (EFR data type); and

means responsive to an entry in the database system which includes a reference of the EFR data type to a file object in the filing system for providing control information on the connection which causes the filing system to control processing of the file object according to constraints established at the database system.

12. The combination of claim 11 further including:

a first interface between the client application and the database system for provision of database access requests which include references to file objects in the filing system and for receipt of responses from the database system that include references to file objects in the filing system; and

a second interface between the client application and the filing system for obtaining file objects from the filing system using references provided through the first interface.

13. The combination of claim 12, further including:

means in the database system for generating a unique token denoting access authorization of the database system to file objects in the filing system; and

means in the filing system for authorizing access to file objects in the filing system through the second interface in response to a unique token generated in the database system.

14. The combination of claim 11, further including means in the filing system responsive to the control information for rejecting requests from filing system users to rename or delete the file object.

15. The combination of claim 11, further including:

means in the database system for defining a relation over the EFR data type, the relation being represented by a table including a column defined over the EFR data type; and

means in the database system for providing a group identification on the connection between the database system and the filing system, the group identification system for identifying every file object referenced in the column.

16. The combination of claim 15, further including:

means in the database system for entering a plurality of tuples in the table, each tuple including EFR data in a field of the column which references a file object in the filing system; and

the means for providing control information having means for providing identification of each file object referenced in the column, the identification including the group identification.

17. The combination of claim 16, further including:

means in the database system for deleting the relationship from the database system;

means for returning control of file objects referenced in the column to the filing system by deleting the referential integrity constraints with respect to the file objects at the filing system, or by deleting file objects referenced in the column from the filing system.

18. The combination of claim 17, further including:

means in the database system for deleting the entry from the database system; and

means responsive to deletion of the entry for returning control of the file object referenced in the entry to the filing system by deleting the referential integrity constraints with respect to the file object at the filing system, or by deleting the file object from the filing system.

24. The combination of claim 11, wherein the file objects are files.

25. The combination of claim 11, wherein the file objects are bit files.

19. A computer program product, comprising:

a computer usable medium having computer readable program code means embodied thereon for enabling a database system to reference file objects stored in a system for filing data (a filing system);

a first computer readable program code means embodied in the medium for casing the database system to create a connection with a filing system for exchange of information between the database system and the filing system respecting file objects in the filing system;

a second computer readable program code means embodied in the medium for defining a data type in the database system for reference to file objects in the filing system (EFR data type); and

a third computer readable program code means embodied in the medium for providing control information on the connection between the database system and the filing system which causes the filing system to control processing of a file object in response to an entry into the database system that includes data of an EFR data type referencing a file object in the filing system.

20. The computer program product of claim 19, further including:

fourth computer readable program code means embodied in the medium for providing a group identification on the connection between the database system and the filing system, the group identification for identifying any file object referenced in a column defined in the database system over the EFR data type included in a table representing a relation of the database system.

26. The computer program product of claim 19, wherein the file objects are files.

27. The computer program product of claim 19, wherein the file objects are bit files.

21. A computer program product, comprising:

a computer useable medium having computer readable program code means embodied thereon for enabling a database system to reference file objects stored in a system for filing data (filing system);

a computer readable code means embodied on the medium for causing a database system to define a data type that references file objects in the filing system that is external to the database system; and

a computer command code means embodied on the medium for directing the filing system to prevent renaming or deletion of a file object in the filing system that is referenced in an entry in the database system by data of the data type.

28. The computer program product of claim 21, wherein the file objects are files.

29. The computer program product of claim 21, wherein the file objects are bit files.