On Bulk-Loading B⁺-trees

B⁺ 트리를 위한 벌크 로드

In this paper, we propose a bulk-load algorithm for $B^+-trees$, the most widely used index structures in database systems. The main characteristic of our algorithm is to simultaneously process all the keys to be placed on each $B^+-trees$ page when accessing the page. This avoids the overhead for accessing the same page multiple times, which results from applying the $B^+-trees$ insertion algorithm repeatedly. For performance evaluation, we analyze our algorithm in terms of the number of disk accesses. The results show that the number of disk accesses excluding those in the redistribution process in identical to the number of $B^+-trees$ pages. Considering that the redistribution process is an unavoidable preprocessing step for bulk-loading, our algorithm requires just one disk access per $B^+-trees$ page, and therefore turns out to be optimal. We also present performance tendancy according to the changes of parameter values via simulation.