Electronic data structure for controlling access to data objects using locks

• US 7,756,813 B2
• Filed: 09/04/2003
• Issued: 07/13/2010
• Est. Priority Date: 09/09/2002
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Fischer, Martin, Pferdekamper, Thorsten
• Primary Examiner(s): Lee; Wilson
• Assistant Examiner(s): SHECHTMAN, CHERYL MARIA
• Application Number:
  US10/526,751
• Publication Number:
  US 20060149736A1
• Time in Patent Office: 2,504 Days
• Field of Search: 707/2, 707/8, 707/9, 707/203, 707/204, 707/200, 718/102, 711/147, 709/210
• US Class Current: 707/781
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files

Abstract

A data structure is provided for preventing access, in a computer system, to a data object having an identifier (ID). The data structure comprises a first lock object, in which the ID of the data object is stored, and in which a link to a storage location of the data object is assigned to the ID, and a second lock object, in which the ID of the data object is stored. In one embodiment, the ID is stored in the second lock object before storing the ID in the first lock object or before assigning the storage location of the data object to the ID in first lock object. Further, the ID is deleted from the second lock object after storing the ID in the first lock object or after assigning the storage location of the data object to the ID in the first lock object. The data object may be accessible by a software application, whereby the access of the software application to the data object is prevented if the ID is stored in the first or second lock object.

Claims

1. A data structure tangibly embodied in a computer-readable storage medium, the data structure preventing access, in a computer system, to a data object stored in a first storage location, the data structure comprising:

a first lock object, in which an ID of the data object is stored by a first process moving the data object from the first storage location to a second storage location, and in which a link to the second storage location storing a copy of the data object is assigned to the ID, the first lock object comprising a table with at least two columns, a first column for storing IDs of data objects and a second column for storing links to copies of the data objects in the second storage location; and

a second lock object, in which the ID is stored by the first process performing an action on the data object before storing the ID in the first lock object or before assigning the second storage location to the ID in the first lock object, the second lock object comprising a one-dimensional data array of IDs of data objects, wherein;

the first process deletes the ID from the second lock object after storing the ID in the first lock object or after assigning the second storage location to the ID in the first lock object, and

a second process is prevented from accessing the data object if the ID is stored in the first lock object or the second lock object by the first process.

2. The data structure of claim 1, wherein the link is a filename or a link to a file.

3. The data structure of claim 1, wherein the first lock object is a file stored in a nonvolatile storage means.

4. The data structure of claim 1, wherein the data object comprises one or more fields of one or more tables and wherein the ID comprises one or more key fields of the one or more tables.

5. The data structure of claim 1, wherein the second process is a data moving process or a data archiving process.

6. The data structure of claim 1, wherein the second lock object is stored in a volatile or nonvolatile storage means.

7. The data structure of claim 1 for use in enterprise resource planning software.

8. A computer system for processing data and preventing access to a data object stored in a first storage location, the computer system comprising:

memory means having program instructions;

input means for entering data;

storage means for storing data;

a processor responsive to the program instructions; and

a data structure comprising;

a first lock object, in which an ID of the data object is stored by a first process moving the data object from the first storage location to a second storage location, and in which a link to the second storage location storing a copy of the data object is assigned to the ID, the first lock object comprising a table with at least two columns, a first column for storing IDs of data objects and a second column for storing links to copies of the data objects in the second storage location; and

a second lock object, in which the ID is stored by the first process performing an action on the data object before storing the ID in the first lock object or before assigning the second storage location to the ID in the first lock object, the second lock object comprising a one-dimensional data array of IDs of data objects, wherein;

the first process deletes the ID from the second lock object after storing the ID in the first lock object or after assigning the second storage location to the ID in the first lock object, and

a second process is prevented from accessing the data object if the ID is stored in the first lock object or the second lock object by the first process.

10. The data structure of claims 8 or 9, wherein the link is a filename or a link to a file.

11. The data structure of claims 8 or 9, wherein the first lock object is a file stored on a nonvolatile storage means.

12. The data structure of claims 8 or 9, wherein the data object comprises one or more fields of one or more tables and wherein the ID comprises one or more key fields of the one or more tables.

13. The data structure of claims 8 or 9, wherein the the second process is a data moving process or a data archiving process.

14. The data structure of claims 8 or 9, wherein the second lock object is stored in a volatile or nonvolatile storage means.

9. A computer readable medium storing executable instructions which, when executed, create a data structure for preventing access, in a computer system, to a data object stored in a first storage location, the data structure comprising:

a first lock object, in which an ID of the data object is stored by a first process moving the data object from the first storage location to a second storage location, and in which a link to the second storage location storing a copy of the data object is assigned to the ID, the first lock object comprising a table with at least two columns, a first column for storing IDs of data objects and a second column for storing links to copies of the data objects in the second storage location; and

a second lock object, in which the ID is stored by the first process performing a action on the data object before storing the ID in the first lock object or before assigning the second storage location to the ID in the first lock object, the second lock object comprising a one-dimensional data array of IDs of data objects, wherein;

the first process deletes the ID from the second lock object after storing the ID in the first lock object or after assigning the second storage location to the ID in the first lock object, and

a second process is prevented from accessing the data object if the ID is stored in the first lock object or the second lock object by the first process.