Khamis, M. A., Ngo, H. Q., Pichler, R., Suciu, D., & Wang, Y. R. (2024). Convergence of datalog over (Pre-) Semirings. Journal of the ACM, 71(2), Article 8. https://doi.org/10.1145/3643027
E192-02 - Forschungsbereich Databases and Artificial Intelligence
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Journal:
Journal of the ACM
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ISSN:
0004-5411
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Date (published):
Apr-2024
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Number of Pages:
55
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Publisher:
ASSOC COMPUTING MACHINERY
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Peer reviewed:
Yes
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Keywords:
Convergence of datalog; Semirings; Boolean space
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Abstract:
Recursive queries have been traditionally studied in the framework of datalog, a language that restricts recursion to monotone queries over sets, which is guaranteed to converge in polynomial time in the size of the input. But modern big data systems require recursive computations beyond the Boolean space. In this article, we study the convergence of datalog when it is interpreted over an arbitrary semiring. We consider an ordered semiring, define the semantics of a datalog program as a least fixpoint in this semiring, and study the number of steps required to reach that fixpoint, if ever. We identify algebraic properties of the semiring that correspond to certain convergence properties of datalog programs. Finally, we describe a class of ordered semirings on which one can use the semi-naïve evaluation algorithm on any datalog program.
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Project title:
Decompose and Conquer: Fast Query Processing via Decomposition: ICT22-011 (WWTF Wiener Wissenschafts-, Forschu und Technologiefonds)