Databases

SQLDroid is a JDBC driver for Android's sqlite database (android.database.sqlite.SQLiteDatabase).

Makes use of SQLite3 in-memory database possible for your Rails tests by preloading the schema.

Firestore in Datastore mode is a NoSQL document database built for automatic scaling, high performance, and ease of application development. Note that google-cloud-datastore-admin-v1 is a version-specific client library. For most uses, we recommend installing the main client library google-cloud-datastore-admin instead. See the readme for more details.

Slim scrooge boosts speed in Rails ActiveRecord Models by only querying the database for what is needed.

Ignore problematic column names (like 'attributes' or 'class') in ActiveRecord models for legacy database schemas

QueryBuilder is an interpreter for the "pseudo sql" language. This language can be used for two purposes: 1. protect your database from illegal SQL by securing queries 2. ease writing complex relational queries by abstracting table internals

LiveJournal module. Post to livejournal, retrieve friends lists, edit entries, sync journal to an offline database.

Redirect ActiveRecord (Rails) reads to slave databases while ensuring all writes go to the master database.

Gioco is a easy to implement gamification gem based on plug and play concept. Doesn't matter if you already have a full and functional database, Gioco will smoothly integrate everything and provide all methods that you might need.

It is a design pattern in key-value databases to use the key to simulate structure, and Nido can take care of that.

Tokyo Tyrant is a package of network interface to the DBM called Tokyo Cabinet. Though the DBM has high performance, you might bother in case that multiple processes share the same database, or remote processes access the database. Thus, Tokyo Tyrant is provided for concurrent and remote connections to Tokyo Cabinet. It is composed of the server process managing a database and its access library for client applications.

Relaxo is versioned document database built on top of git.

Treequel is an LDAP toolkit for Ruby. It is intended to allow quick, easy access to LDAP directories in a manner consistent with LDAP's hierarchical, free-form nature. It's inspired by and modeled after [Sequel][sequel], a kick-ass database library. For more information on how to use it, check out the [manual](manual/index_md.html).

XapianDb is a ruby gem that combines features of nosql databases and fulltext indexing. It is based on Xapian, an efficient and powerful indexing library

Cloud Firestore is a NoSQL document database built for automatic scaling, high performance, and ease of application development. Note that google-cloud-firestore-admin-v1 is a version-specific client library. For most uses, we recommend installing the main client library google-cloud-firestore-admin instead. See the readme for more details.

RailsDbInfo is a Rails engine that quickly shows the database info

an RDF database for usage in ActiveRDF (based on sqlite3)

Query logs like you query your database. https://logs.betterstack.com/

Rails app rake and capistrano tasks to create and restore dumps of database and assets

Use raw SQL to insert database records in bulk. Supports uniqueness constraints, timestamps, and checking for existing records.

Gem adds an "analyze" method to all Active Record query objects. Compatible with PostgreSQL database.

Sets DATABASE_URL, if it's not set already, to the appropriate value out of the Rails config/database.yml

ActiveRecordDistinctOn adds support for `DISTINCT ON` to ActiveRecord. At the time of this writing, PostgreSQL is the only database which supports this syntax; however, this gem has been written with database independence in mind so that if another Arel visitor adds support for `Arel::Nodes::DistinctOn` in the future, it should work seamlessly.

A vendor independent interface for accessing databases, similar to Perl's DBI but compatible with Rails 3

"Squirm is an anti-ORM for database-loving programmers"

OvirtMetrics is an ActiveRecord-based gem for reading the oVirt History database.

Convert back and forth between Heroku-style ENV['DATABASE_URL'] and Sequel/ActiveRecord-style config hashes.

Provides an easy way to do something that is possible in Rails but still a bit close to the metal using store_accessor: create typecasted, persistent attributes that are not columns in the database but stored in the JSON "data" column. Also supports infinite nesting of embedded models.

A framework that allows to write a domain server, that processes commands and creates events. You should have exactly one domain server for your Rails Disco applications. The domain runs in a domain specific database environment. This helps to make sure no other process interferes with the domain. Have a look at the rails-disco documentation on Github for more details.

Contains everything necessary to build and run projection servers for Rails Disco. Projections process events into database models that are optimized for the Rails views. Have a look at the rails-disco documentation on Github for more details.

Currency models currencies, monetary values, foreign exchanges rates. Pulls live and historical rates from http://xe.com/, http://newyorkfed.org/, http://thefinancials.com/. Can store/retrieve historical rate data from database using ActiveRecord. Can store/retrieve Money values using ActiveRecord. For more details, see: http://rubyforge.org/projects/currency/ http://currency.rubyforge.org/ http://currency.rubyforge.org/files/README_txt.html

Em-resque is a version of Resque, which offers non-blocking and non-forking workers. The idea is to have fast as possible workers for tasks with lots of IO like pinging third party servers or hitting the database. The async worker is using fibers through Synchrony library to reduce the amount of callback functions. There's one fiber for worker and if one of the workers is blocking, it will block all the workers at the same time. The idea to use this version and not the regular Resque is to reduce the amount of SQL connections for high-load services. Using one process for many workers gives a better control to the amount of SQL connections. For using Resque please refer the original project. https://github.com/defunkt/resque/ The library adds two rake tasks over Resque: * resque:work_async for working inside the EventMachine

Candy provides simple, transparent object persistence for the MongoDB database. Classes that include Candy modules save all properties to Mongo automatically, can be recursively embedded, and can retrieve records with chainable open-ended class methods, eliminating the need for method calls like 'save' and 'find.'

This gem is a container for the default SQLUNet database files loaded by the 'wordnet' gem if you don't have your own installation of the WordNet databases. It's mostly just a wrapper around the Sqlite database from: http://sqlunet.sourceforge.net/ To use it, just install the gem and then create the WordNet::Lexicon with no arguments.

Mongo database drivers for volt

The gem provides a client for the AllegroGraph 4.x RDF graph database. Features like searching geo-spatial data, type mapping and transactions are supported.

Rails database scrubber and loader, great for seeding your dev db with real but sanitized data

A lightweight and database-level library to transform any Active Record query into analytics data ready for any chart

You can think of Neo4j as a high-performance graph engine with all the features of a mature and robust database. The programmer works with an object-oriented, flexible network structure rather than with strict and static tables yet enjoys all the benefits of a fully transactional, enterprise-strength database. It comes included with the Apache Lucene document database.

From http://edgeguides.rubyonrails.org/active_record_migrations.html#types-of-schema-dumps: There is however a trade-off: db/schema.rb cannot express database specific items such as triggers, stored procedures or check constraints. While in a migration you can execute custom SQL statements, the schema dumper cannot reconstitute those statements from the database. If you are using features like this, then you should set the schema format to :sql. No longer is this the case. You can now use the default schema format (:ruby) and still preserve your check constraints.

Allows you to create data migrations that can be run up and down to insert data into the database.

Related is a Redis-backed high performance distributed graph database.

Batch up your ActiveRecord "touch" operations for better performance. ActiveRecord::Base.delay_touching do ... end. When "end" is reached, all accumulated "touch" calls will be consolidated into as few database round trips as possible.

Simple Ruby usage of the WURFL device capabilities and features database

Decanter aims to reduce complexity in Rails controllers by creating a place for transforming data before it hits the model and database.

RoundhousE is a Professional Database Change and Versioning Management tool

Dumper is a backup management system that offers a whole new way to take daily backups of your databases.

Handle multiple Database conenctions with ActiveRecord Models

Utilize the TVDB API from Ruby to fetch shows, track updates to the tvdb and sync your media database

Read from stand-by databases for ActiveRecord