Data structures for Dynamic Queries: An analytical and experimental evaluation

Abstract

Dynamic Queries is a querying technique for doing range search on multi-key data sets. It is a direct manipulation mechanism where the query is formulated using graphical widgets and the results are displayed graphically preferably within 100 millisec onds. This paper evaluates four data structures, the multilist, the grid file, k-d tree and the quad tree used to organize data in high speed storage for dynamic queries. The effect of factors like size, distribution and dimensionality of data on the storage o verhead and the speed of search is explored. Analytical models for estimating the storage and the search overheads are presented, and verified to be correct by empirical data. Results indicate that multilists are suitable for small (few thousand points) data sets irrespective of the data distribution. For large data sets the grid files are excellent for uniformly distriubuted data, and trees are good for skewed data distributions. There was not significant difference in performance between the tree st ructures.%X additional reference numbers in the format of the next line Also cross-referenced as CAR-TR-715 Also cross-referenced as ISR-TR-94-47 Also cross-referenced as CS-TR-3133 Also cross-referenced as CAR-TR-685 Also cross-referenced as ISR-TR-93-73