From: Tom Hughes <tom@compton.nu>
Date: Fri, 12 Dec 2008 15:17:14 +0000 (+0000)
Subject: Optimise lookup of traces with a given tag.
X-Git-Tag: live~7655
X-Git-Url: https://git.openstreetmap.org/rails.git/commitdiff_plain/9b1b6be3719edfe165d5ae1fce502bc6ffb5de24?hp=2a121cfc41264254bdeee81fc2b4756ab4886c3a

Optimise lookup of traces with a given tag.
---

diff --git a/app/controllers/trace_controller.rb b/app/controllers/trace_controller.rb
index 91ae92b05..bcac11844 100644
--- a/app/controllers/trace_controller.rb
+++ b/app/controllers/trace_controller.rb
@@ -48,8 +48,9 @@ class TraceController < ApplicationController
     
     if params[:tag]
       @tag = params[:tag]
-      conditions[0] += " AND EXISTS (SELECT * FROM gpx_file_tags AS gft WHERE gft.gpx_id = gpx_files.id AND gft.tag = ?)"
-      conditions << @tag
+
+      files = Tracetag.find_all_by_tag(params[:tag]).collect { |tt| tt.gpx_id }
+      conditions[0] += " AND gpx_files.id IN (#{files.join(',')})"
     end
     
     conditions[0] += " AND gpx_files.visible = 1"