From: Sandro Santilli <strk@keybit.net>
Date: Mon, 5 Nov 2012 10:27:08 +0000 (+0000)
Subject: Create indices on start_node and end_node of edge_data  (#2082)
X-Git-Tag: 2.1.0beta2~413
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d42054844e96922e58597ca5a23f78e9c049bb96;p=postgis

Create indices on start_node and end_node of edge_data  (#2082)

Those indices speed up nodes deletion by a factor of x1000 !
I didn't profile, but I suspect those indices would also speed up
ring walking (whereas you have to find a match between endnodes).

git-svn-id: http://svn.osgeo.org/postgis/trunk@10644 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/topology/topology.sql.in.c b/topology/topology.sql.in.c
index b8e67ffe2..09a88c078 100644
--- a/topology/topology.sql.in.c
+++ b/topology/topology.sql.in.c
@@ -1855,6 +1855,19 @@ BEGIN
     || quote_ident(atopology)
     || '.edge_data (right_face);';
 
+  ------- Indexes on start_node and end_node of edge_data
+  ------- NOTE: this indexes speed up node deletion
+  -------       by a factor of 1000 !
+  -------       See http://trac.osgeo.org/postgis/ticket/2082
+  EXECUTE 'CREATE INDEX edge_start_node_idx ON '
+    || quote_ident(atopology)
+    || '.edge_data (start_node);';
+  EXECUTE 'CREATE INDEX edge_end_node_idx ON '
+    || quote_ident(atopology)
+    || '.edge_data (end_node);';
+
+  -- TODO: consider also adding an index on node.containing_face 
+
   ------- Add record to the "topology" metadata table
   EXECUTE 'INSERT INTO topology.topology '
     || '(id, name, srid, precision, hasZ) VALUES ('