SDB101 » Techniques of Query Processing
 
Selection:
  • Unsorted data and no index
  • Spatial Indexing
  • Rank = selectivity - 1/differential cost
selectivity(p): cardinality(output(p))/cardinality(input(p))

differential cost is the cost of the predicate

Última modificación: Saturday, 19 de November de 2005, 09:06