10,173 research outputs found
CoPhy: A Scalable, Portable, and Interactive Index Advisor for Large Workloads
Index tuning, i.e., selecting the indexes appropriate for a workload, is a
crucial problem in database system tuning. In this paper, we solve index tuning
for large problem instances that are common in practice, e.g., thousands of
queries in the workload, thousands of candidate indexes and several hard and
soft constraints. Our work is the first to reveal that the index tuning problem
has a well structured space of solutions, and this space can be explored
efficiently with well known techniques from linear optimization. Experimental
results demonstrate that our approach outperforms state-of-the-art commercial
and research techniques by a significant margin (up to an order of magnitude).Comment: VLDB201
Tractable Optimization Problems through Hypergraph-Based Structural Restrictions
Several variants of the Constraint Satisfaction Problem have been proposed
and investigated in the literature for modelling those scenarios where
solutions are associated with some given costs. Within these frameworks
computing an optimal solution is an NP-hard problem in general; yet, when
restricted over classes of instances whose constraint interactions can be
modelled via (nearly-)acyclic graphs, this problem is known to be solvable in
polynomial time. In this paper, larger classes of tractable instances are
singled out, by discussing solution approaches based on exploiting hypergraph
acyclicity and, more generally, structural decomposition methods, such as
(hyper)tree decompositions
Experimental Study of the Cloud Architecture Selection for Effective Big Data Processing
Big data dictate their requirements to the hardware and software. Simple
migration to the cloud data processing, while solving the problem of increasing
computational capabilities, however creates some issues: the need to ensure the
safety, the need to control the quality during data transmission, the need to
optimize requests. Computational cloud does not simply provide scalable
resources but also requires network infrastructure, unknown routes and the
number of user requests. In addition, during functioning situation can occur,
in which you need to change the architecture of the application - part of the
data needs to be placed in a private cloud, part in a public cloud, part stays
on the client
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