Certified Graph View Maintenance with Regular Datalog. Issue 3 (10th August 2018)

• Record Type: Journal Article
• Authors: BONIFATI, ANGELA; DUMBRAVA, STEFANIA; ARIAS, EMILIO JESÚS GALLEGO
• Editors: Dal Palu, Alessandro; Tarau, Paul
• Is Part Of: Theory and practice of logic programming. Volume 18:Issue 3/4(2018)
• Page Start: 372
• Page End: 389
• Publication Date: 2018-08-10
• Subjects: Regular Datalog, -- Graph Queries, -- Graph Views, -- Incremental Maintenance, -- Finite Semantics, -- Theorem Proving; Logic programming -- Periodicals; Artificial intelligence -- Computer programs -- Periodicals; Constraint programming (Computer science) -- Periodicals; 005.115
• DOI: 10.1017/S1471068418000224
• Languages: English
• ISSNs: 1471-0684

Abstract

Abstract: We employ the Coq proof assistant to develop a mechanically-certified framework for evaluating graph queries and incrementally maintaining materialized graph instances, also called views. The language we use for defining queries and views is Regular Datalog (RD) – a notable fragment of non-recursive Datalog that can express complex navigational queries, with transitive closure as native operator. We first design and encode the theory of RD and then mechanize a RD-specific evaluation algorithm capable of fine-grained, incremental graph view computation, which we prove sound with respect to the declarative RD semantics. By using the Coq extraction mechanism, we test an OCaml version of the verified engine on a set of preliminary benchmarks. Our development is particularly focused on leveraging existing verification and notational techniques to: a) define mechanized properties that can be easily understood by logicians and database researchers and b) attain formal verification with limited effort. Our work is the first step towards a unified, machine-verified, formal framework for dynamic graph query languages and their evaluation engines.