I would like to eliminate overlapping polygons from a table that is often updated with new polygons, but only if a certain attribute has a higher value. If this higher-priority polygon only partly overlaps the lower-priority polygon, only delete the part of the lower-priority polygon that intersects.
As an analogy (not actually my case), let's say we have a table that will contain both U.S. county and state polygons. If I have county (low-priority) polygons for, say, Virginia, and then acquire a state-level (higher-priority) polygon, I would add the state and delete the counties.
On the other hand, if I have a regional (low-priority) polygon, say New England, and add a New Hampshire (high) polygon, punch a hole in the New England polygon, insert New Hampshire, and leave the rest of the New England polygon intact.