Hitachi, Ltd.

Natsuko Mizutani

Atsushi Hatakeyama

Kanji Kato

Katsumi Tada

Hisamitsu Kawaguchi

Satoshi Asakawa

A neighboring plural-character occurrence bitmap of a practical capacity capable of eliminating noises by hashing is realized, and a high speed full text search is realized equivalently, by greatly reducing the number of documents to be searched even if a search term constituted by a combination of English characters and words is used. Text data is segmented into words, and n-character strings at every (m+l)-th character positions are extracted from each word. A neighboring plural-character occurrence bitmap is created which stores data representing a presence of each neighboring plural-character string at a certain entry thereof. N-character strings at every (m+l)-th character positions are extracted from a search term and the neighboring plural-character occurrence bitmap is searched by using a search control program. Since the neighboring plural-character occurrence bitmap is searched prior to searching condensed texts, documents not relevant to the search term can be discarded and a high speed full text search can be realized.

Document search method wherein stored documents and search queries

A text search method for structured documents and apparatus wherein structured document database to be searched is created by adding logical structure length information to logical structure discriminating information on the basis of a structured document constituted by a plurality of logical structures and logical structure discriminator information, and in searching the structured document database in accordance with an entered search key constituted by a logical structure and a search character string, the search of a logical structure other than the entered logical structure is skipped based upon the data length information. In the method and apparatus, by using a structured document, structured document database to be searched is created which is constituted by a condensed text for each logical structure constituted by a list of words contained in the logical structure, a character occurrence bitmap for each logical structure constituted by a list of characters contained in the logical structure and an source structured document, and then the structured document database is searched in accordance with an entered search key constituted by a logical structure and a search character string. An source structured document is searched optionally depending upon the entered search key.

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Kawasaki, Japan

Natsuko Mizutani