FM-index for Dummies
نویسندگان
چکیده
The FM-index is a celebrated compressed data structure for full-text pattern searching. After the first wave of interest in its theoretical developments, we can observe a surge of interest in practical FM-index variants in the last few years. These enhancements are often related to a bit-vector representation, augmented with an efficient rankhandling data structure. In this work, we propose a new, cache-friendly, implementation of the rank primitive and advocate for a very simple architecture of the FM-index, which trades compression ratio for speed. Experimental results show that our variants are 2–3 times faster than the fastest known ones, for the price of using typically 1.5–5 times more space.
منابع مشابه
Reusing an FM-index
Intuitively, if two strings S1 and S2 are sufficiently similar and we already have an FM-index for S1 then, by storing a little extra information, we should be able to reuse parts of that index in an FM-index for S2. We formalize this intuition and show that it can lead to significant space savings in practice, as well as to some interesting theoretical problems.
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تاریخ انتشار 2017