### Abstract

Solving the AllPairs similarity search problem entails finding all pairs of vectors in a high dimensional sparse dataset that have a similarity value higher than a given threshold. The output form this problem is a crucial component in many real-world applications, such as clustering, online advertising, recommender systems, near-duplicate document detection, and query refinement. A number of serial algorithms have been proposed that solve the problem by pruning many of the possible similarity candidates for each query object, after accessing only a few of their non-zero values. The pruning process results in unpredictable memory access patterns that can reduce search efficiency. In this context, we introduce pL2AP, which efficiently solves the AllPairs cosine similarity search problem in a multi-core environment. Our method uses a number of cache-tiling optimizations, combined with fine-grained dynamically balanced parallel tasks, to solve the problem 1.5x- 238x faster than existing parallel baselines on datasets with hundreds of millions of non-zeros.

Original language | English (US) |
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Title of host publication | Proceedings of the 5th Workshop on Irregular Applications |

Subtitle of host publication | Architectures and Algorithms, IA3 2015 |

Publisher | Association for Computing Machinery, Inc |

ISBN (Electronic) | 9781450340014 |

DOIs | |

State | Published - Nov 15 2015 |

Event | 5th Workshop on Irregular Applications: Architectures and Algorithms, IA3 2015 - Austin, United States Duration: Nov 15 2015 → … |

### Publication series

Name | Proceedings of the 5th Workshop on Irregular Applications: Architectures and Algorithms, IA3 2015 |
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### Other

Other | 5th Workshop on Irregular Applications: Architectures and Algorithms, IA3 2015 |
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Country | United States |

City | Austin |

Period | 11/15/15 → … |

### Keywords

- Bounded cosine similarity graph
- Cosine similarity
- Similarity join
- Similarity search

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## Cite this

*Proceedings of the 5th Workshop on Irregular Applications: Architectures and Algorithms, IA3 2015*[a8] (Proceedings of the 5th Workshop on Irregular Applications: Architectures and Algorithms, IA3 2015). Association for Computing Machinery, Inc. https://doi.org/10.1145/2833179.2833182