Use of spatial functions in a query

Using certaim spatial functions in the WHERE clause can influence the Db2® optimizer to consider spatial grid indexes for the access plan.

The spatial functions that have this effect on the Db2 optimizer are:
  • ST_Contains
  • ST_Crosses
  • ST_Distance
  • ST_EnvIntersects
  • EnvelopesIntersect
  • ST_Equals
  • ST_Intersects
  • ST_MBRIntersects
  • ST_Overlaps
  • ST_Touches
  • ST_Within