@inproceedings{2b007930095f492598dd822744a8049b,
title = "Monadic datalog containment",
abstract = "We reconsider the problem of containment of monadic datalog (MDL) queries in unions of conjunctive queries (UCQs). Prior work has dealt with special cases, but has left the precise complexity characterization open. We begin by establishing a 2EXPTIME lower bound on the MDL/UCQ containment problem, resolving an open problem from the early 90's. We then present a general approach for getting tighter bounds on the complexity, based on analysis of the number of mappings of queries into tree-like instances. We use the machinery to present an important case of the MDL/UCQ containment problem that is in co-NEXPTIME, and a case that is in EXPTIME. We then show that the technique can be used to get a new tight upper bound for containment of tree automata in UCQs. We show that the new MDL/UCQ upper bounds are tight.",
author = "Michael Benedikt and Pierre Bourhis and Pierre Senellart",
year = "2012",
month = jan,
day = "1",
doi = "10.1007/978-3-642-31585-5\_11",
language = "English",
isbn = "9783642315848",
series = "Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)",
publisher = "Springer Verlag",
number = "PART 2",
pages = "79--91",
booktitle = "Automata, Languages, and Programming - 39th International Colloquium, ICALP 2012, Proceedings",
edition = "PART 2",
note = "39th International Colloquium on Automata, Languages, and Programming, ICALP 2012 ; Conference date: 09-07-2012 Through 13-07-2012",
}