Optimization for dynamic inverted index maintenance

For free-text search over rapidly evolving corpora, dynamic update of inverted indices is a basic requirement. B-trees are an effective tool in implementing such indices. The Zipfian distribution of postings suggests space and time optimizations unique to this task. In particular, we present two novel optimizations, merge update, which performs better than straight forward block update, and pulsing which significantly reduces space requirements without sacrificing performance.