Micro- and macro-optimizations of SaaT search: Micro- and macro-optimizations of SaaT search

We introduce and test several micro- and macro-optimizations to the Score-at-a-Time approach to processing impact-ordered postings lists in a search engine. Our micro-optimizations are at the single-assembly instruction level, but our macro-optimizations are algorithmic. Overall, we see an improvement of 37% on our baseline (22% on state of the art). We experiment with parallel search and present evidence that we have hit the memory wall.