The Free Termination Property of Queries Over Time

Conor Power, Paraschos Koutris and Joseph M. Hellerstein

EECS Department
University of California, Berkeley
Technical Report No. UCB/EECS-2025-7
February 10, 2025

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2025/EECS-2025-7.pdf

Building on prior work on distributed databases and the CALM Theorem, we define and study the question of free termination: in the absence of distributed coordination, what query properties allow nodes in a distributed (database) system to unilaterally terminate execution even though they may receive additional data or messages in the future? This completeness question is complementary to the soundness questions studied in the CALM literature. We also develop a new model based on semiautomata that allows us to bridge from the relational transducer model of the CALM papers to algebraic models that are popular among software engineers (e.g. CRDTs) and of increasing interest to database theory for datalog extensions and incremental view maintenance.

Advisor: Joseph M. Hellerstein

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BibTeX citation:

@mastersthesis{Power:EECS-2025-7,
    Author = {Power, Conor and Koutris, Paraschos and Hellerstein, Joseph M.},
    Title = {The Free Termination Property of Queries Over Time},
    School = {EECS Department, University of California, Berkeley},
    Year = {2025},
    Month = {Feb},
    URL = {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2025/EECS-2025-7.html},
    Number = {UCB/EECS-2025-7},
    Abstract = {Building on prior work on distributed databases and the CALM Theorem, we define and study the question of free termination: in the absence of distributed coordination, what query properties allow nodes in a distributed (database) system to unilaterally terminate execution even though they may receive additional data or messages in the future? This completeness question is complementary to the soundness questions studied in the CALM literature. We also develop a new model based on semiautomata that allows us to bridge from the relational transducer model of the CALM papers to algebraic models that are popular among software engineers (e.g. CRDTs) and of increasing interest to database theory for datalog extensions and incremental view maintenance.}
}

EndNote citation:

%0 Thesis
%A Power, Conor
%A Koutris, Paraschos
%A Hellerstein, Joseph M.
%T The Free Termination Property of Queries Over Time
%I EECS Department, University of California, Berkeley
%D 2025
%8 February 10
%@ UCB/EECS-2025-7
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2025/EECS-2025-7.html
%F Power:EECS-2025-7