7 papers
Maintaining Queries under Updates Using Heavy-Light Partitioning of the Input Relations
Mahmoud Abo-Khamis, Eden Chmielewski, Andrei Draghici +2
We study the classical incremental view maintenance problem: Given a query and a database, maintain the query output under single-tuple updates (inserts or deletes) to the database…
Acyclic Conjunctive Regular Path Queries are no Harder than Corresponding Conjunctive Queries
Mahmoud Abo Khamis, Alexandru-Mihai Hurjui, Ahmet Kara +2
We present an output-sensitive algorithm for evaluating an acyclic Conjunctive Regular Path Query (CRPQ). Its complexity is written in terms of the input size, the output size, and…
Output-Sensitive Evaluation of Acyclic Conjunctive Regular Path Queries
Mahmoud Abo Khamis, Alexandru-Mihai Hurjui, Ahmet Kara +3
Conjunctive Regular Path Queries, or CRPQs for short, are an essential construct in graph query languages. In this paper, we propose the first output-sensitive algorithm for evalua…
Information Theory Strikes Back: New Development in the Theory of Cardinality Estimation
Mahmoud Abo Khamis, Vasileios Nakos, Dan Olteanu +1
Estimating the cardinality of the output of a query is a fundamental problem in database query processing. In this article, we overview a recently published contribution that casts…
Output-Sensitive Evaluation of Regular Path Queries
Mahmoud Abo Khamis, Ahmet Kara, Dan Olteanu +1
We study the classical evaluation problem for regular path queries: Given an edge-labeled graph and a regular path query, compute the set of pairs of vertices that are connected by…
LpBound: Pessimistic Cardinality Estimation using -Norms of Degree Sequences
Haozhe Zhang, Christoph Mayer, Mahmoud Abo Khamis +2
Cardinality estimation is the problem of estimating the size of the output of a query, without actually evaluating the query. The cardinality estimator is a critical piece of a que…