System and method for a portable document indexing using the N-gram word decomposition

摘要

A system and method provides for indexing and retrieval of stored documents using a decomposition of words in the documents in n- grams, or linear word subunits. The documents are indexed as pages in a number of banks. For each bank there is a bank index. The individual n- grams are identified for each page are stored in the bank index. Each bank index further contains an entry map that indicates whether a given n- gram is present in any of the pages of the bank, and then provides an index to a page map that further indicates which page in the bank contains the n- gram. When a search query is input, the query words are decomposed into their n-grams. The query word n-grams are compared first with entry maps to determine if the query word n-grams appear on any page in the bank. If so, the associated page map is traversed to determine which page in the bank contains the query word n-grams. The n-grams on the page are compared with the query word n-grams to determine the presence of an match therebetween. Matching pages are flagged. When all pages in all banks have been processed, the pages are consolidated with respect to the documents to which they belong, resulting in a list of documents that match the search query. The results are displayed to a user.