In-Place versus Re-Build versus Re-Merge: Index Maintenance Strategies for Text Retrieval Systems

Indexes are the key technology underpinning efficient text search. A range of algorithms have been developed for fast query evaluation and for index creation, but update algorithms for high-performance indexes have not been evaluated or even fully described. In this paper, we explore the three main alternative strategies for index update: in-place update, index merging, and complete re-build. Our experiments with large volumes of web data show that re-merge is for large numbers of updates the fastest approach, but in-place update is suitable when the rate of update is low or buffer size is limited.