Information retrieval system for archiving multiple document versions

• US 9,384,224 B2
• Filed: 11/18/2013
• Issued: 07/05/2016
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Patterson, Anna L
• Primary Examiner(s): Vy, Hung T
• Application Number:
  US14/082,501
• Publication Number:
  US 20140074809A1
• Time in Patent Office: 960 Days
• Field of Search: 707/695, 707/999.003, 707/705, 707/709, 707/722, 707723-728, 707/736, 707/758, 707/661, 707/667, 715/501.1
• US Class Current: 1/1
• CPC Class Codes: G06F 16/219 Managing data history or versioning querying versioned data G06F16/2474; querying temporal data G06F16/2477
• CPC Class Codes: G06F 16/313 Selection or weighting of terms for indexing
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06F 40/197 Version control for software G06F8/71
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching

Abstract

An information retrieval system uses phrases to index, retrieve, organize and describe documents. Phrases are identified that predict the presence of other phrases in documents. Documents ate the indexed according to their included phrases. Index data for multiple versions or instances of documents is also maintained. Each document instance is associated with a date range and relevance data derived from the document for the date range.

Claims

1. A system comprising:

a phrase-based index that includes a plurality of posting lists, each of the posting lists including;

a phrase, and

a list of documents associated with the phrase;

at least one processor; and

memory storing instructions that, when executed by the at least one processor, cause the system to perform operations including;

receiving, on a first date, a current version of a previously indexed version of a document, the previously indexed version being associated with a closed date of a date range that represents current validity,

determining that the current version differs from the previously indexed version,

generating a document identifier for the current version that is based on the first date,

determining at least one phrase associated with the current version,

updating the closed date of the date range for the previously indexed version based on the first date,

setting a closed date of a date range for the current version to a status that represents current validity, and

updating a posting list for the at least one phrase to include the document identifier.

2. The system of claim 1, wherein the date range for the current version begins on the first date and updating the closed date of the date range for the previously indexed version based on the first date includes updating the closed date to a second date, the second date being one day before the first date.

3. The system of claim 1, wherein the memory stores instructions that, when executed by the at least one processor, cause the system to perform further operations including:

receiving a query that includes a third date and that relates to the phrase;

determining that the third date occurs in the date range for the previously indexed version; and

in response, upweighting a relevance score for the previously indexed version.

4. The system of claim 1, wherein the phrase-based index maintains corresponding indexed relevance data for each version of the document.

5. The system of claim 1, wherein the document identifier is a hash of a location for the document and the first date.

6. The system of claim 1, wherein the memory stores instructions that, when executed by the at least one processor, cause the system to perform further operations including:

determining a quantity of versions of the document; and

upweighting a relevance score for the current version of the document when the quantity meets a threshold.

7. The method of claim 1, wherein updating the closed date of the date range for the previously indexed version based on the first date includes setting the closed date to a number of days occurring between an open date for the date range and the first date.

8. The method of claim 1, wherein the status indicating current validity is a non-numerical string.

9. A method comprising:

receiving, on a first date, a current version of a previously indexed version of a document, the previously indexed version being associated with a closed date of a date range that represents current validity;

determining, using at least one processor, that the current version differs from the previously indexed version;

generating, using the at least one processor, a document identifier for the current version that is based on the first date;

determining at least one phrase associated with the current version;

updating the closed date of the date range for the previously indexed version based on the first date;

setting a closed date of a date range for the current version to a status that represents current validity; and

updating a posting list for the at least one phrase to include the document identifier, the posting list being included in a phrase-based index.

10. The method of claim 9, wherein the date range for the current version begins on the first date and updating the closed date of the date range for the previously indexed version based on the first date includes updating the closed date with a second date, the second date being one day before the first date.

11. The method of claim 9, wherein the method further comprises:

receiving a query that includes a third date and that relates to the phrase;

determining that the third date occurs in the date range for the previously indexed version; and

in response, upweighting a relevance score for the previously indexed version.

12. The method of claim 9, wherein the phrase-based index maintains corresponding indexed relevance data for each version of the document.

13. The method of claim 9, wherein the document identifier is a hash of a location for the document and the first date.

14. The method of claim 9, the method further comprising:

determining a quantity of versions of the document; and

upweighting a relevance score for the current version of the document when the quantity meets a threshold.

15. A system comprising:

at least one processor; and

a memory storing;

date specific instances of a document, each instance having an associated date range, the instances including a first version of the document with a first date range having a closed date that indicates the first version is currently valid,

an index relating phrases to instances of documents, and

instructions that, when executed by the at least one processor, cause the system to perform operations comprising;

receiving, on a first date, a second version of the document,

determining that the second version differs from the first version,

updating, in response to the determining, the closed date of the first date range from a status indicating current validity to a date prior to the first date,

associating the second version of the document with a date range having the first date as an open date and a closed date that represents current validity, and

updating the index to relate some of the phrases in the index to the second version of the document.

16. The system of claim 15, wherein the memory stores instructions that, when executed by the at least one processor, cause the system to perform further operations including:

generating a document identifier for the second version that is based on the first date; and

using the document identifier in the updated index.

17. The system of claim 15, wherein the memory stores instructions that, when executed by the at least one processor, cause the system to perform further operations including:

receiving a query that includes a third date and that includes a phrase related to the first version and the second version in the index;

determining that the third date occurs in the date range for the first version; and

upweighting, in response to determining that the third date occurs in the date range, a relevance score for the first version of the document.

18. The system of claim 15, wherein the memory stores instructions that, when executed by the at least one processor, cause the system to perform further operations including:

receiving a query that includes a phrase related to the first version and the second version in the index;

determining that the first version of the document is not currently valid; and

downweighting, in response to determining that the first version is not currently valid, a relevance score for the first version of the document.

19. The system of claim 15, wherein the closed date is a number indicating a number of days following an open date for the date range.