How to Speed Up Phrase Search with bigram_index

TL;DR bigram_index can be used for several purposes, and in this article we focus specifically on phrase-search performance: on the 1M-document benchmark below, bigram_index='all' improved QPS by about 2.9x and cut average phrase-query latency by about 3.2x . If your main problem is matching xt850 against xt 850 rather than speeding up phrase search, see How to Make xt850 Match xt 850 . Phrase search can be expensive. Even when a query is short, the engine still has to verify ordering and adjace