Use production statistics for realistic SQL query analysis. Finds code that may take down production, including missing indexes, overly broad indexes, and queries that return too much data.

Sharding

Introspects your database string field maximum lengths and automatically defines length validations.

Recursively traverse trees using a single SQL query

This gem enables your model to query the database using the earthdistance extension. This should be much faster than using trigonometry functions over standart indexs.

Simple tagging gem for Rails using postgres array.

With Amountable, you can easily attach, organize and sum Ruby money fields to your models without migrating.

CMS built on rails with love.

Give your models as-of date temporal extensions. Built entirely for PostgreSQL >= 9.4

Tracking exceptions for Rails application store them in database by exception_notification gem.

hydra_attribute is an implementation of EAV pattern for ActiveRecord models.

Organizes ActiveRecord models into a tree/hierarchy using a materialized path implementation based around PostgreSQL's ltree datatype. ltree's operators ensure that queries are fast and easily understood.

Ruby gem that automatically adds a lock timeout to all Active Record migrations

Store nested hashes and other types in ActiveRecord hstores

pg-eyeballs is a ruby gem that gives you detailed information about how the SQL queries created by the active record code you write are executed by the database. It gives you an easy, ruby friendly way to see the output of the Postgres EXPLAIN command and integrates with the popular query analysis tool gocmdpev

Organize ActiveRecord model into a tree structure using PostgreSQL LTree

A lightweight cron scheduler for the Que async job worker

Common libraries for RedmineUP plugins (www.redmineup.com) for Redmine. Required Redmine from http://redmine.org

This gem makes Rails console sessions less dangerous in specified environments by warning, color-coding, auto-sandboxing, and allowing read-only external connections (disables job queueing, non-GET requests, etc.)

Track what product being viewed, what being purchased. Who are consistant buyers etc.