Pg is the Ruby interface to the {PostgreSQL
https://bitbucket.org/ged/ruby-pg

Pg is the Ruby interface to the {PostgreSQL
RDBMS}[http://www.postgresql.org/].
It works with {PostgreSQL 9.1 and
later}[http://www.postgresql.org/support/versioning/].
A small example usage:
#!/usr/bin/env ruby
require 'pg'
# Output a table of current connections to the DB
conn = PG.connect( dbname: 'sales' )
conn.exec( "SELECT * FROM pg_stat_activity" ) do |result|
puts "     PID | User             | Query"
result.each do |row|
puts " %7d | %-16s | %s " %
row.values_at('procpid', 'usename', 'current_query')
end
end.