计算机工程与应用
計算機工程與應用
계산궤공정여응용
COMPUTER ENGINEERING AND APPLICATIONS
2015年
11期
114-118,123
,共6页
徐红波%姚念民%韩启龙%潘海为
徐紅波%姚唸民%韓啟龍%潘海為
서홍파%요념민%한계룡%반해위
空间数据库%线段%索引结构%CB树
空間數據庫%線段%索引結構%CB樹
공간수거고%선단%색인결구%CB수
spatial database%line segment%index structure%CB-tree
在空间数据库中点、线段和区域是构成向量对象的三种基本实体。现有的索引结构能够将点或区域对象有效地组织成散列或分层目录,并且提供精确的检索方法。然而,这些索引结构索引线段时会出现以下问题。索引结构不能准确地表示线段的空间信息,这将阻碍对线段空间数据的高质量存储。位于层次目录中节点之间将产生大量死空间和重叠区域,随着时间的推移这将降低系统性能。提出一种采用数据压缩的索引结构CB树。与R树索引结构相比,CB树具有较优查询效率,占用较少存储空间。
在空間數據庫中點、線段和區域是構成嚮量對象的三種基本實體。現有的索引結構能夠將點或區域對象有效地組織成散列或分層目錄,併且提供精確的檢索方法。然而,這些索引結構索引線段時會齣現以下問題。索引結構不能準確地錶示線段的空間信息,這將阻礙對線段空間數據的高質量存儲。位于層次目錄中節點之間將產生大量死空間和重疊區域,隨著時間的推移這將降低繫統性能。提齣一種採用數據壓縮的索引結構CB樹。與R樹索引結構相比,CB樹具有較優查詢效率,佔用較少存儲空間。
재공간수거고중점、선단화구역시구성향량대상적삼충기본실체。현유적색인결구능구장점혹구역대상유효지조직성산렬혹분층목록,병차제공정학적검색방법。연이,저사색인결구색인선단시회출현이하문제。색인결구불능준학지표시선단적공간신식,저장조애대선단공간수거적고질량존저。위우층차목록중절점지간장산생대량사공간화중첩구역,수착시간적추이저장강저계통성능。제출일충채용수거압축적색인결구CB수。여R수색인결구상비,CB수구유교우사순효솔,점용교소존저공간。
Point, line and region are three basic entities which constitute vector-based objects in spatial databases. Exist-ing index structures can effectively organize the objects such as points, regions into hash or hierarchical directory, and pro-vide accurate retrieval methods. However the following questions arise when such methods are applied to line segments. Spatial information of line segments may not be precisely expressed which impedes high-quality conservation of line seg-ments. In the hierarchical directory, a lot of dead space and overlapping regions will be generated between nodes, which degrade the performance over time. The paper presents the index structure CB-tree based on data compression. Compared with R-tree, CB-tree has optimum query efficiency, takes up less storage space.