Information processing apparatus, document retrieval system, document retrieval method, and program

• US 8,612,466 B2
• Filed: 08/14/2009
• Issued: 12/17/2013
• Est. Priority Date: 10/08/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kikuchi, Hiroaki, Nishikawa, Hirofumi
• Primary Examiner(s): Tran, Ahn Tai
• Application Number:
  US13/121,400
• Publication Number:
  US 20110179075A1
• Time in Patent Office: 1,586 Days
• Field of Search: None
• US Class Current: 707/759
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06F 21/6227 where protection concerns the structure of data, e.g. records, types, queries
• CPC Class Codes: G06F 2221/2117 User registration
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: G06F 2221/2145 Inheriting rights or properties, e.g., propagation of permissions or restrictions within a hierarchy

Abstract

An information processing apparatus includes a database management unit that generates an index including access authority for a document and manages the index together with the document, a user information acquisition unit that acquires, as user information, the access authority for a user identification value, a document search unit that acquires the user information and a search request including a search expression, generates a combined search expression by combining an inclusion relationship expression with the search expression, the inclusion relationship expression including an operator that designates an inclusion relationship for access authority of an originator, and acquires a search result at a shared level enabling sharing under a plurality of user identification values in a domain including the plurality of user identification values, and a cache management unit 218 that registers the search result at the shared level as a cache item identified as the one at the shared level.

Claims

1. A computer executable document search method for searching for a document, comprising:

generating, based on user information represented as a group hierarchy having a user identifier and one or more groups joined by one or more operators, an inclusion relationship expression including an operator that designates an inclusion relationship for access authority;

combining the inclusion relationship expression with a received search expression to generate a combined search expression;

for searching at a private level, using the combined search expression to generate a first search expression using the received search expression and specifying the user identifier without specifying the one or more groups; and

for searching at a shared level, using the combined search expression to generate a second search expression using the received search expression and specifying the one or more groups without specifying the user identifier.

2. The document search method according to claim 1, further comprising:

in response to a search request at the shared level,

when a cache item is found at the shared level, returning a search result for the cache item; and

when there is no cache item found at the shared level, executing an index search of an index based on the combined search expression to generate a new search result at the shared level.

3. The document search method according to claim 2, further comprising:

generating a hash value from the second search expression generated from the combined search expression, wherein the second search expression generates the search result at the shared level; and

using the hash value to search for the cache item.

4. The document search method according to claim 1, wherein combining further comprises:

registering the search result generated from executing the first search expression at the private level as a cache item using a hash value generated from the first search expression.

5. The document search method according to claim 4, further comprising:

generating the search result set at the private level by generating a union based on a search result at the shared level and the search result at the private level.

6. The document search method according to claim 1, wherein the access authority is set for each of a private level to which a user has access, a domain level including a plurality of users, and an open domain level including a plurality of domain levels to enable secure search.

7. The document search method according to claim 1, wherein an index that is searched comprises a full-text index generated as an inverted index, and wherein the full-text index further includes access authority indexes registered in a field where words are to be registered.

8. A non-transitory device readable recording medium storing a device readable program and that, when executed by a computer, makes the computer execute:

generating, based on user information represented as a group hierarchy having a user identifier and one or more groups joined by one or more operators, an inclusion relationship expression including an operator that designates an inclusion relationship for access authority;

combining the inclusion relationship expression with a received search expression to generate a combined search expression;

for searching at a private level, using the combined search expression to generate a first search expression using the received search expression and specifying the user identifier without specifying the one or more groups; and

for searching at a shared level, using the combined search expression to generate a second search expression using the received search expression and specifying the one or more groups without specifying the user identifier.

9. The non-transitory device readable recording medium storing the device readable program according to claim 8, that, when executed by a computer, makes the computer execute:

in response to a search request at the shared level, when a cache item is found at the shared level, returning a search result for the cache item; and

when there is no cache item found at the shared level, executing an index search of an index based on the combined search expression to generate a new search result at the shared level.

10. The non-transitory device readable recording medium storing the device readable program according to claim 9, that, when executed by a computer, makes the computer execute:

generating a hash value from the second search expression generated from the combined search expression, wherein the second search expression generates the search result at the shared level; and

using the hash value to search for the cache item.

11. The non-transitory device readable recording medium storing the device readable program according to claim 8, that, when executed by a computer, when combining, makes the computer execute:

registering the search result generated from executing the first search expression at the private level as a cache item using a hash value generated from the first search expression.

12. The non-transitory device readable recording medium storing the device readable program according to claim 11, that, when executed by a computer, when combining, makes the computer execute:

generating the search result set at the private level by generating a union based on a search result at the shared level and the search result at the private level.

13. The non-transitory device readable recording medium storing the device readable program according to claim 8, wherein the access authority is set for each of a private level to which a user has access a domain level including a plurality of users, and an open domain level including a plurality of domain levels to enable secure search.

14. An information processing apparatus that searches for a document, comprising:

a hardware processor; and

a device readable recording medium coupled to the hardware processor, wherein the device readable recording medium stores a program, and wherein the program is executed by the hardware processor to;

generate, based on user information represented as a group hierarchy having a user identifier and one or more groups joined by one or more operators, an inclusion relationship expression including an operator that designates an inclusion relationship for access authority;

combine the inclusion relationship expression with a received search expression to generate a combined search expression;

for searching at a private level, use the combined search expression to generate a first search expression using the received search expression and specifying the user identifier without specifying the one or more groups; and

for searching at a shared level, use the combined search expression to generate a second search expression using the received search expression and specifying the one or more groups without specifying the user identifier.

15. The information processing apparatus according to claim 14, wherein the program is executed by the processor to:

in response to a search request at the shared level,

when the cache item is found at the shared level, return a search result for the cache item; and

when there is no cache item found at the shared level, execute an index search based on the combined search expression to generate a new search result at the shared level.

16. The information processing apparatus according to claim 15, wherein the program is executed by the processor to:

generate a hash value from the second search expression generated from the combined search expression, wherein the second search expression generates the search result at the shared level; and

use the hash value to search for the cache item.

17. The information processing apparatus according to claim 14, wherein the program is executed by the processor to:

register the search result generated from executing the first search expression at the private level as a cache item using a hash value generated from the first search expression.

18. The information processing apparatus according to claim 17, wherein the program is executed by the processor to:

generate the search result set at the private level by generating a union based on a search result at the shared level and the search result at the private level.

19. The information processing apparatus according to claim 14, wherein the access authority is set for each of a private level to which a user has access, a domain level including a plurality of users, and an open domain level including a plurality of domain levels to enable secure search.

20. The information processing apparatus according to claim 14, further comprising:

a terminal device that sends a search request via a network, wherein the search request includes the search expression to enable document search using a user identification value; and

a search server that receives the search request from the terminal device to execute the document search and returns a search result to the terminal device.