SDB101 » Spatial Operations
 
  • Update operations
  • Selection operations:
  • Point Query (PQ): given a query point p, fin all objects O that contain it:
PQ(p) = { O| p є O.G ≠ Ø}
  • Range or region query (WQ): given a query polygon P, find all objects O that intersect P. When P is rectangular, we call it windows query
WQ(P) = { O| O.G Ո P.G ≠ Ø}
  • Spatial aggregation: It is a variant of the search for nearest neighbor. Given an object O’, find objects o that have a minimum distance to o’
NNQ(o’) = { o|fa o’’: dist(o’.G,o.G) ≤ dist(o’.G,o’’.G) }

Última modificación: Saturday, 19 de November de 2005, 08:47