Improvement Of Based_on TPR~*-Tree Index

The spatio-temporal database has received considerable attention in database techniques, due to the emergence of numerous applications. Spatio-temporal database combines temporal data with spatial dataof spatio-temporal objects and handle those data efficiently. The index method is the key technique to support fastly accessing spatio-temporal data.According to the type of spaio-temporal data, index methods of spatio-temporal database generally fall into three categories: index for historical spatio-temporal data, index for current position and index for future position. R-tree has many variances which support different spatio-temporal queries in different organized methods for spatical data and temporal data. Contrail is a prototype system of spatio-temporal database which manages historical spatio-temporal data.Firstly, we introduce the relative knowledge about Spatio-Temporal Databases, and explain the relative conception and theory. At the same time, the indexing and query methods of Spatio-Temporal Databases are classified, respectively.Secondly, we research and analyze the existing main indexing structures in Spatio-Temporal Databases. We mainly introduce the R-tree variants, and emphatically, classify and summarize systematically and completely the indexing methods for moving objects in Spatio-Temporal Databases, and analyze the main ideas and existing advantages and drawbacks, respectively.Specially, we focus on the two most important R-tree based indices, i.e. TPR-Tree and TPR*-tree. We will concentrate on the operations and the corresponding performance. Their deletetion and insertion, which involve from those of R-Tree, have to traverse the tree for several times, resulting in the worst performace in frequent updates. Activated by this, we propose our solution which is called Improved Update LGU-TPR*-Tree.We studied the contribution of Lee et al. on bottom-up update strategy and developed it to be used on TPR*-tree to reduce I/O and CPU Time. In the new algorithm, we uses three auxiliary structures to memory some necessary information to reduce traversals, leading to better update performace.