class ActiveRecord::ConnectionAdapters::MySQL::SchemaDumper

def schema_collation(column)
  if column.collation
    @table_collation_cache ||= {}
    @table_collation_cache[table_name] ||=
      @connection.internal_exec_query("SHOW TABLE STATUS LIKE #{@connection.quote(table_name)}", "SCHEMA").first["Collation"]
    column.collation.inspect if column.collation != @table_collation_cache[table_name]
  end
end