Using both is slightly problematic because they have different
ways to use the index. Newer versions of Postgis exhibit a
query planner issue when both functions appear together.
As ST_Intersects includes ST_Covers, simply remove the latter.
When computing the address parts for a geometry, we need to do
a ST_Relates lookup in the location_area_large_* tables. This is
potentially very expensive for geometries with many vertices.
There is already a funtion for splitting large areas to reduce the
impact. This commit reduces the minimum area of a split, effectively
increasing the number of splits.
The effect on database size is minimal (around 3% increase), while
the indexing speed for streets increases by a good 60%.
So far we've used a buffer around a place node to define its
potential address reach. This had two problems: the buffer was
so large that addresses often contain false positives and the
buffer is really distorted when getting closer to the poles.
Change the buffer here to draw a bounndig box at a certain
distance in meter. This means that we always use the same
box everywhere on the planet and can make the extent much
smaller. Using a box has the advantage that it is much faster
to figure out if a point is within the box.
