Using union in stream query

db/migrate/20110405170101_fix_stream_queries.rb

@@ -0,0 +1,11 @@
+class FixStreamQueries < ActiveRecord::Migration
+  def self.up
+    change_column :posts, :type, :string, :limit => 40
+    remove_index :posts, :type
+  end
+
+  def self.down
+    add_index :posts, :type
+    change_column :posts, :type, :string, :limit => 127
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20110331004720) do
+ActiveRecord::Schema.define(:version => 20110405170101) do
 
   create_table "aspect_memberships", :force => true do |t|
     t.integer  "aspect_id",  :null => false
@@ -245,6 +245,7 @@ ActiveRecord::Schema.define(:version => 20110331004720) do
   end
 
   add_index "posts", ["author_id"], :name => "index_posts_on_person_id"
+  add_index "posts", ["created_at"], :name => "index_posts_on_created_at"
   add_index "posts", ["guid"], :name => "index_posts_on_guid", :unique => true
   add_index "posts", ["mongo_id"], :name => "index_posts_on_mongo_id"
   add_index "posts", ["status_message_id", "pending"], :name => "index_posts_on_status_message_id_and_pending"

lib/diaspora/user/querying.rb

@@ -20,6 +20,7 @@ module Diaspora
         opts[:hidden] ||= false
         order_with_table = 'posts.' + opts[:order]
         opts[:limit] = opts[:limit].to_i * opts[:page].to_i if opts[:page]
+        select_clause ='posts.id, posts.updated_at AS updated_at, posts.created_at AS created_at'
 
         posts_from_others = Post.joins(:contacts).where( :post_visibilities => {:hidden => opts[:hidden]}, :contacts => {:user_id => self.id})
         posts_from_self = self.person.posts
@@ -30,8 +31,11 @@ module Diaspora
           posts_from_self = posts_from_self.joins(:aspect_visibilities).where(:aspect_visibilities => {:aspect_id => opts[:by_members_of]})
         end
 
-        post_ids = Post.connection.execute(posts_from_others.select('posts.id').limit(opts[:limit]).order(order_with_table).to_sql).map{|r| r.first}
-        post_ids += Post.connection.execute(posts_from_self.select('posts.id').limit(opts[:limit]).order(order_with_table).to_sql).map{|r| r.first}
+        posts_from_others = posts_from_others.select(select_clause).limit(opts[:limit]).order(order_with_table)
+        posts_from_self = posts_from_self.select(select_clause).limit(opts[:limit]).order(order_with_table)
+
+        all_posts = "(#{posts_from_others.to_sql}) UNION (#{posts_from_self.to_sql}) ORDER BY #{opts[:order]} LIMIT #{opts[:limit]}"
+        post_ids = Post.connection.execute(all_posts).map{|r| r.first}
 
         Post.where(:id => post_ids, :pending => false, :type => opts[:type]).select('DISTINCT posts.*').limit(opts[:limit]).order(order_with_table)
       end