Traditional file structures that provide multikey access to records, for example, inverted files, are extensions of file structures originally designed for single-key access. They manifest various deficien-cies in particular for multikey access to highly dynamic files. We study the dynamic aspects of tile structures that treat all keys symmetrically, that is, file structures which avoid the distinction between primary and secondary keys. We start from a bitmap approach and treat the problem of file design as one of data compression of a large sparse matrix. This leads to the notions of a grid partition of the search space and of a grid directory, which are the keys to a dynamic file structure called the grid file. This tile system adapts gracefully to its contents under insertions and deletions, and thus achieves an upper hound of two disk accesses for single record retrieval; it also handles range queries and partially specified queries efficiently. We discuss in detail the design decisions that led to the grid file, present simulation results of its behavior, and compare it to other multikey access file structures.

An important problem in database systems is answering queries quickly. This paper surveys a number of algorithms for efficiently answering range queries. First a set of “loGical structures ” is described and ‘then their implementation in primary and secondary memories is discussed. The algorithms included are of both “practical ” and “theoretical ” interest. Although some new results are presented, the primary purpose of this paper is to collect together the known results on range searching and to present them in a common terminology.

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