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Data sort method, data sort apparatus, and data sort program

  • US 7,103,596 B2
  • Filed: 03/04/2002
  • Issued: 09/05/2006
  • Est. Priority Date: 07/27/2001
  • Status: Active Grant
First Claim
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1. A data sort method of rearranging records according to a specified sort key item in an ascending/descending order, comprising:

  • an automaton generating step of generating, in a main memory, an automaton which receives a character string of a sort key item of each record read successively from outside, and which is a set of state transition tables with a hierarchical tree structure whose hierarchical depth is equal to a maximum number of characters of a character string of a sort key item of each record, and whose transition table corresponds to each character of a character string of the sort key item of each record, and also whose state transition table contains links to next stage state transition tables each of which corresponds to a next character of a character string of the sort key item of each record in an ascending/descending order according to each of the next characters, and which associates a record identifier of each record with a final state transition table corresponding to the final character of a character string of the sort key item of the record; and

    an order value tuple generating step of generating an order value tuple which is a set of a record identifier of the record and an order value which is obtained by arranging the records in an ascending/descending order by scanning the automaton in order of contained links in the state transition tables giving priority to the depth direction of the hierarchy of the state transition tables.

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