无法在Heroku上启动Rails应用程序

我正在尝试将rails应用程序部署到heroku,但仍然会出现以下错误。我本以为管理Postgres宝石是Heroku会处理的事情。

除了在本地机器上安装postgres,我已经尝试了所有我能想到的方法,如果我想安装postgres gem,我就需要这么做。也没有宝石叫 activerecord-postgresql-adapter …我猜这是Rails附带的标准适配器吧??

你有什么想法吗?

App failed to start

/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:76:in `establish_connection': Please install the postgresql adapter: `gem install activerecord-postgresql-adapter` (no such file to load -- pg) (RuntimeError)
from /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:60:in `establish_connection'
from /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:55:in `establish_connection'
from /usr/local/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:438:in `initialize_database'
from /usr/local/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:141:in `process'
from /usr/local/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `send'
from /usr/local/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `run'
from /disk1/home/slugs/135415_c7f31f0_9f1f/mnt/config/environment.rb:9
from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
 ... 14 levels...
from /usr/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/builder.rb:29:in `instance_eval'
from /usr/local/lib/ruby/gems/1.8/gems/rack-1.0.1/lib/rack/builder.rb:29:in `initialize'
from /home/heroku_rack/heroku.ru:1:in `new'
from /home/heroku_rack/heroku.ru:1