COMPUTER-IMPLEMENTED METHOD, COMPUTER PROGRAM PRODUCT AND SYSTEM FOR CREATING AN INDEX OF A SUBSET OF DATA

• US 20080294597A1
• Filed: 09/04/2007
• Published: 11/27/2008
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Dassault Systemes SA
• Original Assignee: Exalead SA (Dassault Systemes SA)
• Inventors: Douetteau, Florian, Bourdoncle, Francois, Donze, Stephane
• Granted Patent: US 8,010,501 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/328 Management therefor

Abstract

The invention is directed to a method, computer program product and computer system for creating an index of a subset of data, comprising:

• • a first step of receiving:
    • a set of data;
    • a first index of said set of data; and
    • identifiers of a subset of data of said set; and
  • a second step of creating a second index of said subset of data according to the first index and said identifiers.

Claims

1. A computer-implemented method for creating an index of a subset of data, comprising:

a first step Of receiving;

a set of data;

a first index of said set of data; and

identifiers of a subset of data of said set; and

a second step of creating a second index according to the first index and said identifiers, said second index being an index of said subset of data.

2. The method of claim 1, wherein the first index created at the first step is an inverted file index.

3. The method of claim 1, wherein the second step does not make use of data of the set which are not in the subset or identifiers of data of the set which are not in the subset.

4. The method of claim 1, wherein the second step comprises comparing the first index with said identifiers.

5. The method of claim 4, wherein the set of data comprises a plurality of documents, said subset being a subset of said documents.

6. The method of claim 5, wherein the first index created at the first step is an inverted file index storing a mapping from words to said documents.

7. The method of claim 6, wherein said first index comprises a plurality of inverted lists, each of said lists corresponding to a respective word of said words.

8. The method of claim 7, wherein the step of comparing the first index with said identifiers comprises computing, for each said words, an intersection of its respective list with said identifiers.

9. The method of claim 7 wherein each of said inverted lists is sorted and compressed.

10. The method of claim 1, wherein a same software component is used for implementing the first and second steps.

11. The method of claim 1, wherein the first step further comprises selecting said subset of data according to the received first index and a criterion.

12. The method of an claim 1, wherein:

the first step comprises receiving a plurality of sets of identifiers, each set of identifiers corresponding to a respective subset of data of said set; and

the second step comprises;

creating a plurality of second indexes according to the first index and said sets of identifiers, each of said second indexes being an index of a respective subset of data.

13. The method of claim 1, further comprising:

a third step of updating the first index and storing first residual data, such that the updated first index can be computed according to the index as before updating and said first residual data; and

a fourth step of

updating the second index according to said first residual data and identifiers of the subset of data, and

storing second residual data, such that the updated second index can be computed according to the second index before updating and second residual data.

14. A computer program product implementing the method according to claim 1.

15. A computer system comprising means adapted for implementing the method of claim 1.