remove public share visibilities. NOTE: you should run optimize table as detailed in the migration's comments after executing this. [ci skip]

db/migrate/20120202190701_remove_public_share_visibilities.rb

@@ -0,0 +1,37 @@
+# NOTE: this migration will remove a lot of unused rows.  It is highly suggested
+# that you run `OPTIMIZE TABLE share_visibilities` after this
+# migration is complete.
+#
+# caution: you may want to take your pod offline during the OPTIMIZE command.
+
+class RemovePublicShareVisibilities < ActiveRecord::Migration
+  class ShareVisibility < ActiveRecord::Base; end
+
+  def self.up
+    %w{Post Photo}.each do |type|
+
+      index = 0
+      visibilitiy_size = ShareVisibility.count
+
+      while index < visibilitiy_size + 100 do
+        sql = <<-SQL
+          DELETE sv
+            FROM share_visibilities AS sv
+              INNER JOIN posts
+              ON sv.shareable_id = posts.id
+              WHERE sv.shareable_type = "#{type}"
+                AND #{type.tableize}.public IS TRUE
+                AND #{type.tableize}.id < #{index};
+        SQL
+
+        ActiveRecord::Base.connection.execute(sql)
+
+        index += 100
+      end
+    end
+  end
+
+  def self.down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20120114191018) do
+ActiveRecord::Schema.define(:version => 20120202190701) do
 
   create_table "account_deletions", :force => true do |t|
     t.string  "diaspora_handle"