| In
traditional DB, the computational cost of a query is defined in terms
of I/O. In a spatial DB, in contrast, the fact that the system deals
with complex data makes the definition of a query plan and optimization
more relevant The query optimizer generates different evaluation planes and selects one. Many times, time is not the best, but at least, it is not the worst. The activities of the optimizer can be classified into: logical transformation and dynamic programming |
Última modificación: Saturday, 19 de November de 2005, 09:27