>> DB = Sequel('postgres://postgres:postgres@localhost/reality_development')

>> schema = DB.schema

>> schema.class
=> Sequel::InformationSchema

>> schema.database == DB
=> true

>> schema.tables # (table_schema = :public)
#  t = DB[:"INFORMATION_SCHEMA.TABLES"].filter(:table_schema => 'public')
=> [:nodes, ...]

>> schema.tables(:information_schema) # specify table_schema
=> [:triggers, :tables, ...]

>> schema.columns(:nodes) # (table_name, table_schema = :public)
#  t = DB[:"INFORMATION_SCHEMA.COLUMNS"].filter(:table_schema => 'public', :table_name => 'nodes')
=> [{:name => :id, :type => :integer, :unique => true, ...}, ...blahblah]

# column info:

  :name => :blah
  :type => :blah
  :null => true|false
  :default => blah