Scalable semantic querying of text
Xiaolan Wang, Aaron Feng, Behzad Golshan, Alon Y. Halevy, George A. Mihaila, Hidekazu Oiwa, Wang-Chiew Tan · Proceedings of the VLDB Endowment · 2018
We present the Koko system that takes declarative information extraction to a new level by incorporating advances in natural language processing techniques in its extraction language. K oko is novel in that its extraction language simultaneously supports conditions on the surface of the text and on the structure of the dependency parse tree of sentences, thereby allowing for more refined extractions. K oko also supports conditions that are forgiving to linguistic variation of expressing concepts and allows to aggregate evidence from the entire document in order to filter extractions. To scale up, K oko exploits a multi-indexing scheme and heuristics for efficient extractions. We extensively evaluate K oko over publicly available text corpora. We show that K oko indices take up the smallest amount of space, are notably faster and more effective than a number of prior indexing schemes. Finally, we demonstrate K oko 's scalability on a corpus of 5 million Wikipedia articles.