Uniform Storage Model-based Update Scheme of On-line Information Retrieval System
In order to improve the retrieval performance of on-line information retrieval systems, an efficient index update scheme is proposed in this paper, which can provide better skipping function and further enhance both space and time efficiencies without inserting any additional auxiliary information. A uniform storage model (USM) is proposed to manage both short and long postings lists based on link. A USM-based update scheme also is proposed to distinguish long and short posting lists, which merges short lists with immediately merge, and merges long lists with improved Y-limited contiguous multiple merge scheme, which balances the trade-off of the time and space efficiencies effectively. The proposed update scheme not only considers both index level and inverted list level update, but also effectively improves time and space efficiencies of index update. Detailed experimental results and comparison with existed schemes show that the proposed scheme greatly averagely reduces space cost, conjunctive Boolean query time, and the cost of on-line index construction