Add bounding box optimisation to distance query

lib/geocoder/stores/active_record.rb

@@ -100,15 +100,18 @@ module Geocoder::Store
         options[:units] ||= (geocoder_options[:units] || Geocoder::Configuration.units)
         bearing = bearing_sql(latitude, longitude, options)
         distance = distance_sql(latitude, longitude, options)
+
+        b = Geocoder::Calculations.bounding_box([latitude, longitude], radius, options)
+        args = b + [
+          full_column_name(geocoder_options[:latitude]),
+          full_column_name(geocoder_options[:longitude])
+        ]
+        bounding_box_conditions = Geocoder::Sql.within_bounding_box(*args)
+
         if using_sqlite?
-          b = Geocoder::Calculations.bounding_box([latitude, longitude], radius, options)
-          args = b + [
-            full_column_name(geocoder_options[:latitude]),
-            full_column_name(geocoder_options[:longitude])
-          ]
-          conditions = Geocoder::Sql.within_bounding_box(*args)
+          conditions = bounding_box_conditions
         else
-          conditions = ["#{distance} <= ?", radius]
+          conditions = [bounding_box_conditions + " AND #{distance} <= ?", radius]
         end
         {
           :select => select_clause(options[:select], distance, bearing),

test/near_test.rb

@@ -8,7 +8,10 @@ class NearTest < Test::Unit::TestCase
       :select =>
         "test_table_name.*, 3958.755864232 * 2 * ASIN(SQRT(POWER(SIN((1.0 - test_table_name.latitude) * PI() / 180 / 2), 2) + COS(1.0 * PI() / 180) * COS(test_table_name.latitude * PI() / 180) * POWER(SIN((2.0 - test_table_name.longitude) * PI() / 180 / 2), 2))) AS distance, CAST(DEGREES(ATAN2( RADIANS(test_table_name.longitude - 2.0), RADIANS(test_table_name.latitude - 1.0))) + 360 AS decimal) % 360 AS bearing",
       :conditions =>
-        ["3958.755864232 * 2 * ASIN(SQRT(POWER(SIN((1.0 - test_table_name.latitude) * PI() / 180 / 2), 2) + COS(1.0 * PI() / 180) * COS(test_table_name.latitude * PI() / 180) * POWER(SIN((2.0 - test_table_name.longitude) * PI() / 180 / 2), 2))) <= ?", 5],
+        [
+          "test_table_name.latitude BETWEEN 0.927634108444576 AND 1.072365891555424 AND test_table_name.longitude BETWEEN 1.9276230850898697 AND 2.07237691491013 AND 3958.755864232 * 2 * ASIN(SQRT(POWER(SIN((1.0 - test_table_name.latitude) * PI() / 180 / 2), 2) + COS(1.0 * PI() / 180) * COS(test_table_name.latitude * PI() / 180) * POWER(SIN((2.0 - test_table_name.longitude) * PI() / 180 / 2), 2))) <= ?",
+          5
+        ],
       :order => "distance ASC"
     }