[ANN] Rails 0.9.3: Optimistic locking, dynamic finders, Ruby 1.8.2 compatible

Rails is now fully compatible with Ruby 1.8.2, which we advice all to upgrade to as soon as possible. It contains a year's worth of bug fixes for Ruby, so it's great finally to be able to use the new version with Rails. But that is not all we got in store for 0.9.3. A few of the highlights are:

* Automated optimistic locking: Just add the field @lock_version@ to your table and the associated class will be governed by optimistic locking that'll raise an exception if a stale object attempts to save.

* Dynamic finders: Finders like Person.find_by_user_name, Payment.find_by_amount, and even Person.find_by_user_name_and_password are now available with no code at all. Any column can be used and combined with other columns in the new dynamic finders.

* MS SQL Server and DB2: Active Record now supports both Microsoft SQL Server (through ADO) and IBM's DB2 databases.

* MemCacheStore for sessions: You can now store sessions in Action Pack using Danga's memcache technology.

* Generators guard against reserved words:* Not only will ./script/generate model Thread be denied, you'll also get a list of synonyms pulled live from WordNet!

That's just a small taste of the 35 changes, fixes, and features introduced with Rails 0.9.3. You can read the full story in the changelogs:

* Active Record: http://ar.rubyonrails.com/files/CHANGELOG.html
* Action Pack : http://ap.rubyonrails.com/files/CHANGELOG.html
* Rails : http://rails.rubyonrails.com/files/CHANGELOG.html

The new web presence



Since the last release, we've also launched a brand new website and visual identity for Rails. This includes the long awaited logo by John Hicks with a remix by Olivier Hericord. Check it all out at: http://www.rubyonrails.org

Upgrading from Rails 0.9.2 to 0.9.3

There's only one change you need to make in order to have your application updated from 0.9.2 to 0.9.3. In the config/environments/production.rb and config/environments/test.rb, you need to change:

   ActionController::Base.reload_dependencies = false
   ActiveRecord::Base.reload_associations = false


   Dependencies.mechanism = :require<

And in config/environments/development.rb, you need to change:

   ActionController::Base.reload_dependencies = true
   ActiveRecord::Base.reload_associations = true


   Dependencies.mechanism = :load

If you're coming on from 0.8.x, you'll need to go through the <a href="http://manuals.rubyonrails.com/read/book/3">Upgrading to 0.9 manual</a>.
David Heinemeier Hansson,
http://www.basecamphq.com/ -- Web-based Project Management
http://www.rubyonrails.org/ -- Web-application framework for Ruby
http://macromates.com/ -- TextMate: Code and markup editor (OS X)
http://www.loudthinking.com/ -- Broadcasting Brain