Online index rebuild
Nagavamsi Ponnekanti, Hanuma Kodavalla · ACM SIGMOD Record · 2000
In this paper we present an efficient method to do online rebuild of a B+-tree index. This method has been implemented in Sybase Adaptive Server Enterprise (ASE) Version 12.0. It provides high concurrency, does minimal amount of logging, has good performance and does not deadlock with other index operations. It copies the index rows to newly allocated pages in the key order so that good space utilization and clustering are achieved. The old pages are deallocated during the process. Our algorithm differs from the previously published online index rebuild algorithms in two ways. It rebuilds multiple leaf pages and then propagates the changes to higher levels. Also, while propagating the leaf level changes to higher levels, level 1 1 pages are reorganized, eliminating the need for a separate pass. Our performance study shows that our approach results in significant reduction in logging and CPU time. Also, our approach uses the same concurrency control mechanism as split and shrink operations, which made it attractive for implementation.