Two doubts about Oracle Spatial.

Hi,

I've just read the documentation of Oracle Spatial and I've got a few doubts (I hope you can help me with some of them...):

1. What is the difference between an operator and a function?. It seems that both return a value. However, in the documentacion it is said (for example) that SDO_nn is an operator while SDO_GEOM.WITHIN_DISTANCE is a function. I don't see the difference. Anyone can clarify me this?.
2. A spatial join without mask is suppossed to return "pairs of GID values that interact in their index entries". What does "to interact" mean in this context?. Does it mean to retrieve objects that overlap?. For example:

SELECT A.GID, B.GID
FROM PARKS A, HIGHWAYS B
WHERE sdo_filter(A.shape, B.shape, 'querytype=join') = 'TRUE';

3) Does GID mean "Greographic ID"?.

Thanks in advance Received on Wed Apr 23 2003 - 15:17:14 CDT