Answer Happy

Spatial query processing uses a two-step 'Filter-Refine' strategy. Which part of this strategy is supported by creating a spatial index on the data, such as an R-Tree? O Refine part: the R-Tree allows to efficiently find a candidate set of geometries overlapping the query region. O None as the R-Tree is only used for a spatial join. O Both parts: an R-Tree can be used to initially filter the data using bounding boxes around geometries, but then once on the leaf-level, can give access to the specific boundaries for the Refine part too. O Filter part: the R-Tree allows to efficiently find a candidate set of geometries overlapping the query region.