In [1], Hamzeh, Iranmanesh Hossein-Zadeh and M. V. Diudea recently introduced the generalized degree distance of graphs. In this paper, we present explicit formulas for this new graph invariant of the Cartesian product, composition, join, disjunction and symmetric difference of graphs and introduce generalized and modified generalized degree distance polynomials of graphs, such that their first...

We reduce the set of classic relational algebra operators to two binary operations: natural join and generalized union. We further demonstrate that this set of operators is relationally complete and honors lattice axioms.

In this paper we propose a highly accurate approximate performance analysis of a heterogeneous server system with a processor sharing (PS) service discipline and a general job-size distribution under a generalized join the shortest queue (GJSQ) routing protocol. The GJSQ routing protocol is a natural extension of the well-known join the shortest queue (JSQ) routing policy that takes into accoun...

This paper introduces a generalization of the classical parallel-server fork-join queueing system in which arriving customers fork into multiple tasks, every task is uniquely assigned to one of the set of single-server queues, and each task consists of multiple iterations of different stages of execution, including task vacations and communication among sibling tasks. Several classes of dynamic...

We propose a new class of algorithms that can be used to speed up the execution of multi-way join queries or of queries that involve one or more joins and a group-by. These new evaluation techniques allow to perform several hash-based operations (join and grouping) in one pass without repartitioning intermediate results. These techniques work particularly well for joining hierarchical structure...

Applications for large-scale data analysis use such techniques as parallel DBMS, MapReduce (MR) paradigm, and columnar storage. In this paper we focus in a MapReduce environment. The aim of this work is to compare the different join algorithms and designing cost models for further use in the query optimizer.

Barrier synchronization is widely used in shared-memory parallel programs to synchronize between phases of data-parallel algorithms. With proliferation of many-core processors, barrier synchronization has been adapted for higher level language abstractions in new languages such as X10 wherein the processes participating in barrier synchronization are not known a priori, and the processes in dis...