Instead of unconditionally parenting them to a street, the
larger areas get a parent area that contains them. To keep
things computationally light-weight, only use the centroid and
bbox to determine if an area is contained.
Requires renaming of parenting functions because renaming
a parameter of the function causes issues when updating the
function (it requires a manual delete, which I'd like to
avoid).
Normally ST_Covers() should include a bbox index use,
so adding a bbox where clause is not really necessary.
However, the query planner messes up and uses a parallel
index search with a second index instead of exclusively
running on the geometry index, when the bbox part is
missing.
