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factor out SQL for filtering by location

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Also improves on the decision if an indexed is used or not.
This commit is contained in:
Sarah Hoffmann
2023-12-06 10:55:21 +01:00
parent b06f5fddcb
commit b6c8c0e72b
1 changed files with 27 additions and 20 deletions
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47
nominatim/api/search/db_searches.py
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@@ -55,12 +55,29 @@ NEAR_PARAM: SaBind = sa.bindparam('near', type_=Geometry)
NEAR_RADIUS_PARAM: SaBind = sa.bindparam('near_radius')
COUNTRIES_PARAM: SaBind = sa.bindparam('countries')
def _within_near(t: SaFromClause) -> Callable[[], SaExpression]:
return lambda: t.c.geometry.within_distance(NEAR_PARAM, NEAR_RADIUS_PARAM)
def filter_by_area(sql: SaSelect, t: SaFromClause,
details: SearchDetails, avoid_index: bool = False) -> SaSelect:
""" Apply SQL statements for filtering by viewbox and near point,
if applicable.
"""
if details.near is not None and details.near_radius is not None:
if details.near_radius < 0.1 and not avoid_index:
sql = sql.where(t.c.geometry.within_distance(NEAR_PARAM, NEAR_RADIUS_PARAM))
else:
sql = sql.where(t.c.geometry.ST_Distance(NEAR_PARAM) <= NEAR_RADIUS_PARAM)
if details.viewbox is not None and details.bounded_viewbox:
sql = sql.where(t.c.geometry.intersects(VIEWBOX_PARAM,
use_index=not avoid_index and
details.viewbox.area < 0.2))
return sql
def _exclude_places(t: SaFromClause) -> Callable[[], SaExpression]:
return lambda: t.c.place_id.not_in(sa.bindparam('excluded'))
def _select_placex(t: SaFromClause) -> SaSelect:
return sa.select(t.c.place_id, t.c.osm_type, t.c.osm_id, t.c.name,
t.c.class_, t.c.type,
@@ -449,11 +466,7 @@ class CountrySearch(AbstractSearch):
if details.excluded:
sql = sql.where(_exclude_places(t))
if details.viewbox is not None and details.bounded_viewbox:
sql = sql.where(lambda: t.c.geometry.intersects(VIEWBOX_PARAM))
if details.near is not None and details.near_radius is not None:
sql = sql.where(_within_near(t))
sql = filter_by_area(sql, t, details)
results = nres.SearchResults()
for row in await conn.execute(sql, _details_to_bind_params(details)):
@@ -486,10 +499,7 @@ class CountrySearch(AbstractSearch):
.where(tgrid.c.country_code.in_(self.countries.values))\
.group_by(tgrid.c.country_code)
if details.viewbox is not None and details.bounded_viewbox:
sql = sql.where(tgrid.c.geometry.intersects(VIEWBOX_PARAM))
if details.near is not None and details.near_radius is not None:
sql = sql.where(_within_near(tgrid))
sql = filter_by_area(sql, tgrid, details, avoid_index=True)
sub = sql.subquery('grid')
@@ -542,19 +552,16 @@ class PostcodeSearch(AbstractSearch):
penalty: SaExpression = sa.literal(self.penalty)
if details.viewbox is not None:
if details.bounded_viewbox:
sql = sql.where(t.c.geometry.intersects(VIEWBOX_PARAM))
else:
penalty += sa.case((t.c.geometry.intersects(VIEWBOX_PARAM), 0.0),
(t.c.geometry.intersects(VIEWBOX2_PARAM), 0.5),
else_=1.0)
if details.viewbox is not None and not details.bounded_viewbox:
penalty += sa.case((t.c.geometry.intersects(VIEWBOX_PARAM), 0.0),
(t.c.geometry.intersects(VIEWBOX2_PARAM), 0.5),
else_=1.0)
if details.near is not None:
if details.near_radius is not None:
sql = sql.where(_within_near(t))
sql = sql.order_by(t.c.geometry.ST_Distance(NEAR_PARAM))
sql = filter_by_area(sql, t, details)
if self.countries:
sql = sql.where(t.c.country_code.in_(self.countries.values))