MARINE CHART DATABASE HAVING THREE-TIER INDEX ARCHITECTURE AND METHOD FOR READING DATA THEREFROM

摘要

The invention relates to indexing of marine chart data, and more particularly, to a marine chart database having a three-tier index architecture and a method for reading data therefrom. The invention designs a marine chart index in a marine chart database so that a marine chart can be retrieved via the marine chart index. An internal index is designed for each marine chart, and the internal index comprises an object category index and an object index for the corresponding marine chart. The object category index and the object index are sequentially searched according to a category attribute and a feature attribute of an object needing to be displayed in a target display area so as to locate and display the object needing to be displayed. The three-tier index architecture significantly increases a speed of reading marine chart data, thereby increasing a marine chart display speed.