diff --git a/Gemfile b/Gemfile
index faa4328..a72e420 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,14 +1,10 @@
-source 'https://ruby.taobao.org/'
+source 'https://rubygems.org'
 
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '4.2.3'
-# Use sqlite3 as the database for Active Record
-# gem 'sqlite3'
-#
-gem 'mongoid', '~> 4.0.2'
-gem 'bson_ext'
-
+# Use postgresql as the database for Active Record
+gem 'pg'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/Gemfile.lock b/Gemfile.lock
index 1284963..e803c06 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,5 +1,5 @@
 GEM
-  remote: https://ruby.taobao.org/
+  remote: https://rubygems.org/
   specs:
     actionmailer (4.2.3)
       actionpack (= 4.2.3)
@@ -39,8 +39,6 @@ GEM
     arel (6.0.2)
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
-    bson (3.1.2)
-    bson_ext (1.5.1)
     builder (3.2.2)
     byebug (5.0.0)
       columnize (= 0.9.0)
@@ -52,7 +50,6 @@ GEM
       execjs
     coffee-script-source (1.9.1.1)
     columnize (0.9.0)
-    connection_pool (2.2.0)
     debug_inspector (0.0.2)
     erubis (2.7.0)
     execjs (2.5.2)
@@ -74,20 +71,10 @@ GEM
     mime-types (2.6.1)
     mini_portile (0.6.2)
     minitest (5.7.0)
-    mongoid (4.0.2)
-      activemodel (~> 4.0)
-      moped (~> 2.0.0)
-      origin (~> 2.1)
-      tzinfo (>= 0.3.37)
-    moped (2.0.6)
-      bson (~> 3.0)
-      connection_pool (~> 2.0)
-      optionable (~> 0.2.0)
     multi_json (1.11.2)
     nokogiri (1.6.6.2)
       mini_portile (~> 0.6.0)
-    optionable (0.2.0)
-    origin (2.1.1)
+    pg (0.18.2)
     rack (1.6.4)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -154,12 +141,11 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  bson_ext
   byebug
   coffee-rails (~> 4.1.0)
   jbuilder (~> 2.0)
   jquery-rails
-  mongoid (~> 4.0.2)
+  pg
   rails (= 4.2.3)
   sass-rails (~> 5.0)
   sdoc (~> 0.4.0)
diff --git a/config/application.rb b/config/application.rb
index 42f6ead..71065ff 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -1,18 +1,6 @@
 require File.expand_path('../boot', __FILE__)
 
-# require 'rails/all'
-
-
-require "action_controller/railtie"
-require "action_mailer/railtie"
-# require "active_resource/railtie" # Comment this line for Rails 4.0+
-require "rails/test_unit/railtie"
-
-require "bson"
-require "moped"
-
-Moped::BSON = BSON
-
+require 'rails/all'
 
 # Require the gems listed in Gemfile, including any gems
 # you've limited to :test, :development, or :production.
@@ -33,6 +21,6 @@ module LibrX
     # config.i18n.default_locale = :de
 
     # Do not swallow errors in after_commit/after_rollback callbacks.
-    # config.active_record.raise_in_transactional_callbacks = true
+    config.active_record.raise_in_transactional_callbacks = true
   end
 end
diff --git a/config/database.yml b/config/database.yml
new file mode 100644
index 0000000..8390743
--- /dev/null
+++ b/config/database.yml
@@ -0,0 +1,85 @@
+# PostgreSQL. Versions 8.2 and up are supported.
+#
+# Install the pg driver:
+#   gem install pg
+# On OS X with Homebrew:
+#   gem install pg -- --with-pg-config=/usr/local/bin/pg_config
+# On OS X with MacPorts:
+#   gem install pg -- --with-pg-config=/opt/local/lib/postgresql84/bin/pg_config
+# On Windows:
+#   gem install pg
+#       Choose the win32 build.
+#       Install PostgreSQL and put its /bin directory on your path.
+#
+# Configure Using Gemfile
+# gem 'pg'
+#
+default: &default
+  adapter: postgresql
+  encoding: unicode
+  # For details on connection pooling, see rails configuration guide
+  # http://guides.rubyonrails.org/configuring.html#database-pooling
+  pool: 5
+
+development:
+  <<: *default
+  database: LibrX_development
+
+  # The specified database role being used to connect to postgres.
+  # To create additional roles in postgres see `$ createuser --help`.
+  # When left blank, postgres will use the default role. This is
+  # the same name as the operating system user that initialized the database.
+  #username: LibrX
+
+  # The password associated with the postgres role (username).
+  #password:
+
+  # Connect on a TCP socket. Omitted by default since the client uses a
+  # domain socket that doesn't need configuration. Windows does not have
+  # domain sockets, so uncomment these lines.
+  #host: localhost
+
+  # The TCP port the server listens on. Defaults to 5432.
+  # If your server runs on a different port number, change accordingly.
+  #port: 5432
+
+  # Schema search path. The server defaults to $user,public
+  #schema_search_path: myapp,sharedapp,public
+
+  # Minimum log levels, in increasing order:
+  #   debug5, debug4, debug3, debug2, debug1,
+  #   log, notice, warning, error, fatal, and panic
+  # Defaults to warning.
+  #min_messages: notice
+
+# Warning: The database defined as "test" will be erased and
+# re-generated from your development database when you run "rake".
+# Do not set this db to the same as development or production.
+test:
+  <<: *default
+  database: LibrX_test
+
+# As with config/secrets.yml, you never want to store sensitive information,
+# like your database password, in your source code. If your source code is
+# ever seen by anyone, they now have access to your database.
+#
+# Instead, provide the password as a unix environment variable when you boot
+# the app. Read http://guides.rubyonrails.org/configuring.html#configuring-a-database
+# for a full rundown on how to provide these environment variables in a
+# production deployment.
+#
+# On Heroku and other platform providers, you may have a full connection URL
+# available as an environment variable. For example:
+#
+#   DATABASE_URL="postgres://myuser:mypass@localhost/somedatabase"
+#
+# You can use this database configuration with:
+#
+#   production:
+#     url: <%= ENV['DATABASE_URL'] %>
+#
+production:
+  <<: *default
+  database: LibrX_production
+  username: LibrX
+  password: <%= ENV['LIBRX_DATABASE_PASSWORD'] %>
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 12293d7..b55e214 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -20,7 +20,7 @@ Rails.application.configure do
   config.active_support.deprecation = :log
 
   # Raise an error on page load if there are pending migrations.
-  # config.active_record.migration_error = :page_load
+  config.active_record.migration_error = :page_load
 
   # Debug mode disables concatenation and preprocessing of assets.
   # This option may cause significant delays in view rendering with a large
diff --git a/config/secrets.yml b/config/secrets.yml
index 2f0e41e..cd4994d 100644
--- a/config/secrets.yml
+++ b/config/secrets.yml
@@ -11,10 +11,10 @@
 # if you're sharing your code publicly.
 
 development:
-  secret_key_base: cfe697da7b107061ee88db1c34ce27733c72ca6c1d8b55bc85c553984ad3d429b08f34ab22a2886ae7fdb4eae81a454a7348e08219ab886c51773fd54e60938b
+  secret_key_base: 3cdddef29e0c14a8effb2353cf02b4ff0ae115992e44367078221b41c0ee94b24001b673ccd1c1df85173eab8c4b1dd9b246bece9a9bae7b486ca489b6fb538a
 
 test:
-  secret_key_base: b7ce8141cea97b2a683fcda7d429274b3f316ff87b507cc629957d611098598cf432cabed64396fe588311dbcd01a767b03ec586b39ee81a952f9985ac5ae431
+  secret_key_base: a81364a125879696daabe23a23ebdb1577e03275cc83d80e9e3c109c57a34a16002c33ba7ecebc6f005b8ca80aae7515207da53dc45594561caa353804c7b5ea
 
 # Do not keep production secrets in the repository,
 # instead read values from the environment.
diff --git a/db/schema.rb b/db/schema.rb
new file mode 100644
index 0000000..ea89ed5
--- /dev/null
+++ b/db/schema.rb
@@ -0,0 +1,19 @@
+# encoding: UTF-8
+# This file is auto-generated from the current state of the database. Instead
+# of editing this file, please use the migrations feature of Active Record to
+# incrementally modify your database, and then regenerate this schema definition.
+#
+# Note that this schema.rb definition is the authoritative source for your
+# database schema. If you need to create the application database on another
+# system, you should be using db:schema:load, not running all the migrations
+# from scratch. The latter is a flawed and unsustainable approach (the more migrations
+# you'll amass, the slower it'll run and the greater likelihood for issues).
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema.define(version: 0) do
+
+  # These are extensions that must be enabled in order to support this database
+  enable_extension "plpgsql"
+
+end