Evaluating Mid-(k, n) Queries Using B⁺-Tree

Abstract

Traditional database systems assume that clients always consume the results of queries from the beginning. In various new applications especially in WWW, however, clients frequently need a small part of the result from the middle, e.g. retrieving a page in a bulletin board in WWW. To process this partial retrieval, traditional database systems should find all the records and discard unnecessary ones. Although several algorithms for top-k queries have been proposed, there has been no research effort for partial retrieving from the middle of an ordered result. In this paper, we define a mid-(k,n) query, which retrieves n records from the k ^th record of an ordered result. We also propose an efficient algorithm for mid-(k,n) queries using a slightly modified B⁺-Tree, named the B^+ c-Tree. We provide the theoretical analysis and the experimental results that the proposed technique evaluates mid-(k,n) queries efficiently.

This work was supported in part by the Brain Korea 21 Project and in part by the Ministry of Information & Communications, Korea, under the Information Technology Research Center (ITRC) Support Program in 2005.