ARQo: The Architecture for an ARQ Static Query Optimizer

In this paper we describe the architecture of ARQo, a rst approach for SPARQL static query optimization in ARQ. Speci cally, we focus on static optimization of BasicGraphPattern (BGP) for in-memory models. Static query optimization is intended as a query rewriting process where the set of triple patterns de ned for a BGP are rewritten according to a speci c order. We propose a rewriting process according to the estimated execution cost of joined triple patterns in increasing order. Speci cally, the estimated execution cost is a function of multiple parameters such as the estimated selectivity of joined triple patterns, the availability of indexes or precalculated result sets.