From: Sandro Santilli <strk@kbt.io>
Date: Sat, 3 Dec 2016 22:05:08 +0000 (+0000)
Subject: 4x speed improvement in GetFaceByPoint
X-Git-Tag: 2.4.0alpha~195
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f345052648297045d89c31e331de0497eaf1baf3;p=postgis

4x speed improvement in GetFaceByPoint

Implies a speedup in topology loading too, whereas the
face-containing-point callback is used twice per added line.

git-svn-id: http://svn.osgeo.org/postgis/trunk@15269 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/topology/postgis_topology.c b/topology/postgis_topology.c
index 7665c6149..cbd3ecdc5 100644
--- a/topology/postgis_topology.c
+++ b/topology/postgis_topology.c
@@ -2529,8 +2529,9 @@ cb_getFaceContainingPoint( const LWT_BE_TOPOLOGY* topo, const LWPOINT* pt )
   }
   /* TODO: call GetFaceGeometry internally, avoiding the round-trip to sql */
   appendStringInfo(sql,
-                   "SELECT face_id FROM \"%s\".face "
-                   "WHERE mbr && $1 AND _ST_Contains("
+                   "WITH faces AS ( SELECT face_id FROM \"%s\".face "
+                   "WHERE mbr && $1 ORDER BY ST_Area(mbr) ASC ) "
+                   "SELECT face_id FROM faces WHERE _ST_Contains("
                    "topology.ST_GetFaceGeometry('%s', face_id), $1)"
                    " LIMIT 1",
                    topo->name, topo->name);