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arXiv · 1711.08475

Lightweight Fingerprints for Fast Approximate Keyword Matching Using Bitwise Operations

Aleksander Cisłak·Szymon Grabowski
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Abstract

We aim to speed up approximate keyword matching by storing a lightweight, fixed-size block of data for each string, called a fingerprint. These work in a similar way to hash values; however, they can be also used for matching with errors. They store information regarding symbol occurrences using individual bits, and they can be compared against each other with a constant number of bitwise operations. In this way, certain strings can be deduced to be at least within the distance $k$ from each other (using Hamming or Levenshtein distance) without performing an explicit verification. We show experimentally that for a preprocessed collection of strings, fingerprints can provide substantial speedups for $k = 1$, namely over $2.5$ times for the Hamming distance and over $10$ times for the Levenshtein distance. Tests were conducted on synthetic and real-world English and URL data.

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Aleksander Cisłak, Szymon Grabowski. 2017-11-22. Lightweight Fingerprints for Fast Approximate Keyword Matching Using Bitwise Operations. https://arxiv.org/abs/1711.08475

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