| 摘要 |
PROBLEM TO BE SOLVED: To provide a method that updates a database without copying all data by placing a non-updated part of the database in a read-only medium, and placing an updated part in a local writable medium by a version management method used for concurrency control. SOLUTION: The oldest version of a page is stored in a base page area 21. In response to a writing operation on a page, a database file accessing means 14 duplicates the version in the base page area 21 or a version page area 22 into the version page area 22, and operates the version in the version page area 22. For a writing operation on a page 3, the latest version in a file storage position in the base page area is duplicated into a file storage position y in the version page area 22, and y is operated. COPYRIGHT: (C)2003,JPO
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