This gems allows you to easily create extra databases to your rails application, and freely allocate ActiveRecord instances to any of the databases. It also provides rake tasks and migrations to help you manage the schema by shard groups.

A Rails Engine that enables you to easily wire up a Rails app to an existing Wordpress database

Adds support in ActiveRecord for foreign_keys, complex indexes and other database-related stuff. Easily create foreign_keys, complex indexes and views.

Flexible but opinionated framework for defining and running reports on Rails models backed by SQL databases.

Rubix provides abstractions for connecting to Zabbix's API, an ORM for wrapping Zabbix resources, a set of scripts for writing data to Zabbix, and a collection of Monitor classes for building periodic monitors.

Manage model with a period on ActiveRecord.

State of the Nation makes modeling object history easy.

Statistic and analysis in Ruby DSL, just as simple as SQL operations in ActiveRecord.

Support for DB transactions with Capybara

Manage delta indexes via Sidekiq for Thinking Sphinx

Allows rails models to work as the edges and nodes of a directed acyclic graph (dag). The edges may be typed.

Create associations that combine multiple Active Record associations using a SQL UNION under the hood, with full support for joins, preloading and eager loading on the union association, as well as through-union associations.

This Vagrant plugin allows you to configure a vm environment as a node in a client/server infraestructure. See also vagrant-nodemaster

Keep your code DRY by inferring column validations from table properties! Automagically validate presence, length, numericality, inclusion and uniqueness of ActiveRecord backed columns.

Token based authentication. To support backend authentication for ios, android, angular, ember etc...

Support for binary UUIDs in ActiveRecord

TO DO *is* a description

Mutex that can be used to synchronise ruby processes via an ActiveRecord datababase connection. (Only Mysql is supported at the moment.)

Something with the combination of Rails 3.1, Mysql2 0.3.x, Capybara, Selenium/Webkit/etc causes Mysql to raise exceptions where the connection is waiting on a result. This gem provides an auto-retry capability with the Mysql2Adapter to retry any query execution up to 5 times. This is a a temporary solution until the real issue with the above libraries/frameworks are resolved. This should NOT be used in production.

An ActiveRecord extension for enabling SQL_CACHE and SQL_NO_CACHE in MySQL queries