| 摘要 |
A method of using a DOS file system to access a file in a database is provided. In one embodiment implemented in an on-board vehicle navigation system, the file includes map data for a given geographic area. A file access table (FAT) is associated with the file system and references the file. The FAT has a plurality of locations, each location including a reference to one of the data clusters of the file and to another location in the FAT, forming a linked list of the references. The logical order in which the data clusters occur within the file is determined by following the linked list in the FAT for that file. A cluster table is then constructed, 603 for the file. The references to the data clusters are stored in consecutive locations of the cluster table according to the logical order of the data clusters within the file. The file is then accessed by sequentially accessing the consecutive locations in the cluster table to retrieve the data clusters.
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