class ActiveRecord::InternalMetadata

:nodoc:
‘use_metadata_table` to false in your database configuration.
This is enabled by default. To disable this functionality set
as which environment migrations were run in.
This class is used to create a table that keeps track of values and keys such

def [](key) 

def [](key)
  return unless enabled?
  where(key: key).pick(:value)
end

def []=(key, value) 

def []=(key, value)
  return unless enabled?
  find_or_initialize_by(key: key).update!(value: value)
end

def create_table

Creates an internal metadata table with columns +key+ and +value+ 
def create_table
  return unless enabled?
  unless connection.table_exists?(table_name)
    connection.create_table(table_name, id: false) do |t|
      t.string :key, **connection.internal_string_options_for_primary_key
      t.string :value
      t.timestamps
    end
  end
end

def drop_table 

def drop_table
  return unless enabled?
  connection.drop_table table_name, if_exists: true
end

def enabled? 

def enabled?
  ActiveRecord::Base.connection.use_metadata_table?
end

def primary_key 

def primary_key
  "key"
end

def table_name 

def table_name
  "#{table_name_prefix}#{internal_metadata_table_name}#{table_name_suffix}"
end