Adding pagination to the changesets, thus allowing you to browe large changesets, without MySQL complaining about memory. Probably needs some fine tuning. You currently can only page one of nodes, ways, and relations, without manually setting the relations. Fixing deprection notice for the classic_pagination plugin.

app/controllers/browse_controller.rb

@@ -116,6 +116,9 @@ class BrowseController < ApplicationController
   def changeset
     begin
       @changeset = Changeset.find(params[:id])
+      @node_pages, @nodes = paginate(:old_nodes, :conditions => {:changeset_id => @changeset.id}, :per_page => 20, :parameter => 'node_page')
+      @way_pages, @ways = paginate(:old_ways, :conditions => {:changeset_id => @changeset.id}, :per_page => 20, :parameter => 'way_page')
+      @relation_pages, @relations = paginate(:old_relations, :conditions => {:changeset_id => @changeset.id}, :per_page => 20, :parameter => 'relation_page')
       
       @title = "Changeset | #{@changeset.id}"
       @next = Changeset.find(:first, :order => "id ASC", :conditions => [ "id > :id", { :id => @changeset.id }] ) 

app/helpers/browse_helper.rb

@@ -1,2 +1,5 @@
 module BrowseHelper
+  def link_to_page(page, page_param)
+    return link_to(page, page_param => page)
+  end
 end

app/views/browse/_changeset_details.rhtml

@@ -5,6 +5,11 @@
     <td><%= h(changeset_details.created_at) %></td>
   </tr>
   
+  <tr>
+    <th>Closed at:</th>
+    <td><%= h(changeset_details.closed_at) %></td>
+  </tr>
+  
   <% if changeset_details.user.data_public? %>
     <tr>
       <th>Belongs to:</th>
@@ -21,27 +26,33 @@
         </table>
       </td>
     </tr>
-    <% end %>
+  <% else %>
+    <tr>
+      <th>Tags</th>
+      <td>There are no tags for this changeset</td>
+    </tr>
+  <% end %>
 
-  <% unless changeset_details.old_nodes.empty? %>
+  <% unless @nodes.empty? %>
     <tr valign="top">
-      <th>Has the following nodes:</th>
+      <th>Has the following <%= @node_pages.item_count %> nodes:</th>
       <td>
         <table padding="0">
-          <% changeset_details.old_nodes.each do |node| %>
+          <% @nodes.each do |node| %>
             <tr><td><%= link_to "Node #{node.id.to_s}, version #{node.version.to_s}", :action => "node", :id => node.id.to_s %></td></tr>
           <% end %>
         </table>
       </td>
     </tr>
+    <%= render :partial => 'paging_nav', :locals => { :pages => @node_pages, :page_param => "node_page"} %>
   <% end %>
   
-  <% unless changeset_details.old_ways.empty? %>
+  <% unless @ways.empty? %>
     <tr valign="top">
-      <th>Has the following ways:</th>
+      <th>Has the following <%= @way_pages.item_count %> ways:</th>
       <td>
         <table padding="0">
-          <% changeset_details.old_ways.each do |way| %>
+          <% @ways.each do |way| %>
             <tr><td><%= link_to "Way #{way.id.to_s}, version #{way.version.to_s}", :action => "way", :id => way.id.to_s %></td></tr>
           <% end %>
           <%=
@@ -49,20 +60,22 @@
           %>
         </table>
       </td>
-    </tr>      
+    </tr>
+    <%= render :partial => 'paging_nav', :locals => { :pages => @way_pages, :page_param => "way_page" } %>
   <% end %>
   
-  <% unless changeset_details.old_relations.empty? %>
+  <% unless @relations.empty? %>
     <tr valign="top">
-      <th>Has the following relations:</th>
+      <th>Has the following <%= @relation_pages.item_count %> relations:</th>
       <td>
         <table padding="0">
-          <% changeset_details.old_relations.each do |relation| %>
+          <% @relations.each do |relation| %>
             <tr><td><%= link_to "Relation #{relation.id.to_s}, version #{relation.version.to_s}", :action => "relation", :id => relation.id.to_s %></td></tr>
           <% end %>
         </table>
       </td>
     </tr>
+    <%= render :partial => 'paging_nav', :locals => { :pages => @relation_pages, :page_param => "relation_page" } %>
   <% end %>
 
 </table>

app/views/browse/_paging_nav.rhtml

@@ -0,0 +1,15 @@
+<tr><td colspan='2'>
+<% current_page = pages.current_page %>
+
+Showing page 
+<%= current_page.number %> (<%= current_page.first_item %><% 
+if (current_page.first_item < current_page.last_item) # if more than 1 trace on page 
+  %>-<%= current_page.last_item %><% 
+end %>
+of <%= pages.item_count %>)
+
+<% if pages.page_count > 1 %>
+| <%= pagination_links_each(pages, {}) { |n| link_to_page(n, page_param) } %>
+<% end %>
+</td>
+</tr>

vendor/plugins/classic_pagination/lib/pagination.rb

@@ -97,8 +97,8 @@ module ActionController
             "Unknown options: #{unknown_option_keys.join(', ')}" unless
               unknown_option_keys.empty?
 
-      options[:singular_name] ||= Inflector.singularize(collection_id.to_s)
-      options[:class_name]  ||= Inflector.camelize(options[:singular_name])
+      options[:singular_name] ||= ActiveSupport::Inflector.singularize(collection_id.to_s)
+      options[:class_name]  ||= ActiveSupport::Inflector.camelize(options[:singular_name])
     end
 
     # Returns a paginator and a collection of Active Record model instances