[PDF] Top 20 Parallelizing Federated SPARQL Queries in Presence of Replicated Data

... Abstract. Federated query engines have been enhanced to exploit new data localities created by replicated data, ...aware federated query engines mainly focus on pruning sources during ... Voir le document complet

... Implementations: FedX ` Fedra implementation 5 (in Java) has been modified to preserve the multiple sources that provide the same relevant frag- ments. Additionally, FedX join processing has been modified to ... Voir le document complet

... redundant data. Contrarily to LILAC, the engines are not aware of the replicated fragments, and consequently, they may incur in redundant data ...ble of achieving a reduction as ... Voir le document complet

... published in [ 56 ]. To address our second issue, the SPARQL endpoints poor availability, several strategies may be ...Linked Data Fragments (LDF) [ 81 ] have been proposed to exploit client ... Voir le document complet

... 1.0 in the majority of the cases. In few cases the recall was considerably reduced, but these cases correspond to queries with OPTIONAL operator using the FedX query engine, and it was due to ... Voir le document complet

... Abstract. Federated query engines allow data consumers to execute queries over the federation of Linked Data ...ated queries are decomposed into potentially thousands of ... Voir le document complet

... focus in the first scenario of replicating a precise dataset version (scenario discussed in Section 1), and whose solutions can be combined with divergence metrics for scenarios where latest dataset ... Voir le document complet

... exists. In our running example there is no common endpoint that replicates both f 6 and f ...also replicated at C1, then only C1 would be selected to execute ...part of Eptpq ...element of the ... Voir le document complet

... to data sharing and thus can scale to very large amounts of data and ...examples of P2P systems such as Gnutella [12] and KaaZa [15] have millions of users sharing petabytes of ... Voir le document complet

... scientists in the field of ...development of diseases and insect attacks in the agricultural farms by using sensors, aiming at using pesticides only when ...their data about different ... Voir le document complet

... the data source selection ...Majority of the participants understood how data source selection works for our federated query processor system when the explanation was given ...impact of ... Voir le document complet

... number of remote requests: measured as the number of requests sent to endpoints for ...amount of messages exchanged and the resulting network load. In each run, our hybrid strategy (optimized ... Voir le document complet

... updating of decentralized stores leads immediately to the question of synchronization, as raised by Berners-Lee ...copy of each involved dataset at each site, but this quickly falls out because ... Voir le document complet

... traces of concurrent federated queries, we implemented a tool that shuffles logs of queries executed in isolation to produce different sequences of E(F Q 1 k ...vary ... Voir le document complet

... detection of a provider failure, the query to another ...which queries have been stopped, and rescheduling stopped ...adequate in this context as it does not make this assumption. It allocates ... Voir le document complet

... Abstract. SPARQL property path queries provide a concise way to write complex navigational queries over RDF knowledge ...evaluation of these queries over online knowledge graphs such as ... Voir le document complet

... convergents et commutatifs Résumé : La cohérence à terme vise à assurer que les répliques d’un objet partagé modifiable convergent sans synchronisation à priori. Les approches antérieures du problème sont ad-hoc et ... Voir le document complet

... size of the intersection between the obtained answers and the expected answers divided by the number of expected answers; where the expected answers are the ones obtained from an endpoint containing the ... Voir le document complet

... deployment of their ...pitfalls of their own 6 . In particular, figuring out the appropriate size of a micro-service (its functional scope) is critical in many ...help in the ... Voir le document complet

... State of the Art Recent work on predicting database query performance [2, 13, 14] has argued that the analytical costs models used by the current generation query optimizers are good for comparing alternative ... Voir le document complet