File organizations with shared overflow blocks for variable length objects

摘要

Traditional file organizations for records may also be appropriate for the storage and retrieval of objects. Since objects frequently involve diverse data types (such as text, compressed images, graphics, etc.) as well as composite structures, they may have a largely variable length. In this paper, we assume that in the case of composite objects their components are clustered together and that object file organizations have overflows. The blocks of the main file are grouped so that they share a common number of overflow blocks. For this class of file organizations we present and analyze the performance of three different overflow searching algorithms. We show that the third algorithm gives very significant performance advantages under certain circumstances.