Abstract : As the complexity of the Semantic Web increases, efficient ways to query the Semantic Web data is becoming increasingly impor-tant. Moreover, consumers of the Semantic Web data may need expla-nations for debugging or understanding the reasoning behind producing the data. In this paper, firstly we address the problem of SPARQL query performance prediction. Secondly we discuss how to explain Linked Data in a decentralized fashion. Finally we discuss how to summarize the ex-planations.