From 8a4c7f6e2b5f46fca1adbfbe1718a273a3d43760 Mon Sep 17 00:00:00 2001
From: Sarah Hoffmann <lonvia@denofr.de>
Date: Wed, 26 Feb 2020 10:14:28 +0100
Subject: [PATCH] simplify getNearestParallelRoadFeature function

The function only ever returns one result of which only the
place_id is used. So simplify it to return a single place_id
only (or NULL if none is found).

Also fix typo in function name.
---
 sql/partition-functions.src.sql | 36 ++++++++++++++++-----------------
 sql/tiger_import_start.sql      |  5 ++---
 2 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/sql/partition-functions.src.sql b/sql/partition-functions.src.sql
index 4a8f9139..dbe34363 100644
--- a/sql/partition-functions.src.sql
+++ b/sql/partition-functions.src.sql
@@ -242,19 +242,22 @@ BEGIN
   RAISE EXCEPTION 'Unknown partition %', in_partition;
 END
 $$
-LANGUAGE plpgsql;
+LANGUAGE plpgsql IMMUTABLE;
 
-create or replace function getNearestParellelRoadFeature(in_partition INTEGER, line GEOMETRY) RETURNS setof nearfeature AS $$
+CREATE OR REPLACE FUNCTION getNearestParallelRoadFeature(in_partition INTEGER,
+                                                         line GEOMETRY)
+  RETURNS BIGINT
+  AS $$
 DECLARE
-  r nearfeature%rowtype;
-  search_diameter FLOAT;  
+  r RECORD;
+  search_diameter FLOAT;
   p1 GEOMETRY;
   p2 GEOMETRY;
   p3 GEOMETRY;
 BEGIN
 
-  IF st_geometrytype(line) not in ('ST_LineString') THEN
-    RETURN;
+  IF ST_GeometryType(line) not in ('ST_LineString') THEN
+    RETURN NULL;
   END IF;
 
   p1 := ST_LineInterpolatePoint(line,0);
@@ -265,25 +268,22 @@ BEGIN
   IF in_partition = -partition- THEN
     search_diameter := 0.0005;
     WHILE search_diameter < 0.01 LOOP
-      FOR r IN 
-        SELECT place_id, null, null, null,
-            ST_Distance(geometry, line) as distance, null as isguess
-            FROM location_road_-partition-
-            WHERE ST_DWithin(line, geometry, search_diameter)
-            ORDER BY (ST_distance(geometry, p1)+
-                      ST_distance(geometry, p2)+
-                      ST_distance(geometry, p3)) ASC limit 1
+      FOR r IN
+        SELECT place_id FROM location_road_-partition-
+          WHERE ST_DWithin(line, geometry, search_diameter)
+          ORDER BY (ST_distance(geometry, p1)+
+                    ST_distance(geometry, p2)+
+                    ST_distance(geometry, p3)) ASC limit 1
       LOOP
-        RETURN NEXT r;
-        RETURN;
+        RETURN r.place_id;
       END LOOP;
       search_diameter := search_diameter * 2;
     END LOOP;
-    RETURN;
+    RETURN NULL;
   END IF;
 -- end
 
   RAISE EXCEPTION 'Unknown partition %', in_partition;
 END
 $$
-LANGUAGE plpgsql;
+LANGUAGE plpgsql IMMUTABLE;
diff --git a/sql/tiger_import_start.sql b/sql/tiger_import_start.sql
index 5f916501..4b9c33fc 100644
--- a/sql/tiger_import_start.sql
+++ b/sql/tiger_import_start.sql
@@ -63,9 +63,8 @@ BEGIN
   END IF;
 
   IF out_parent_place_id IS NULL THEN
-    FOR location IN SELECT place_id FROM getNearestParellelRoadFeature(out_partition, linegeo) LOOP
-      out_parent_place_id := location.place_id;
-    END LOOP;    
+    SELECT getNearestParallelRoadFeature(out_partition, linegeo)
+      INTO out_parent_place_id;
   END IF;
 
   IF out_parent_place_id IS NULL THEN
-- 
2.39.5