I'm wondering what is the unit for the optional arguments min_resolution and max_resolution to the function SDO_FILTER. I assume it is the default unit of measurement of the coordinate system of the given geometries, but I can't find any statement on it in the Oracle Spatial Developers Guide for 11g.
As per oracle documentation:
The min_resolution keyword includes only geometries for which at least one side of the geometry's MBR is equal to or greater than the specified value. For example, min_resolution=10 includes only geometries for which the width or the height (or both) of the geometry's MBR is at least 10. (This keyword can be used to exclude geometries that are too small to be of interest.)
The max_resolution keyword includes only geometries for which at least one side of the geometry's MBR is less than or equal to the specified value. For example, max_resolution=10 includes only geometries for which the width or the height (or both) of the geometry's MBR is less than or equal to 10. (This keyword can be used to exclude geometries that are too large to be of interest.)
In Easy Words
Example Query: SELECT c.mkt_id, c.name FROM cola_markets c WHERE SDO_FILTER(c.shape, SDO_GEOMETRY(2003, NULL, NULL,SDO_ELEM_INFO_ARRAY(1,1003,3), SDO_ORDINATE_ARRAY(4,6, 8,8)), 'min_resolution=4.1' ) = 'TRUE';
Whenever we need to exclude some geometries which are smaller than the specified limit (if any) or geometries which are larger than limit (if any), then we use this min_resolution/max_resolution parameter with our query.
min_resolution/max_resolution is height/width of that target geometry MBR (geometry to exclude).
Units of Measurement
The default unit of measure is the one associated with the georeferenced coordinate system. The unit of measure for most coordinate systems is the meter, and in these cases the default unit for distances is meter and the default unit for areas is square meter.