create table parameters (
  name text not null,
  in text references parameter_in_types not null,
  description text,
  required boolean not null,
  schema ,
  type text,
  format text,
  allow_empty_value boolean,
  items ,
  collection_format text references collection_format_types,
  default text,
  maximum bigint,
  exclusive_maximum boolean,
  minimum bigint,
  exclusive_minimum boolean,
  max_length integer,
  min_length integer,
  pattern text,
  max_items integer,
  min_items integer,
  unique_items boolean,
  enum ,
  multiple_of bigint
);
comment on table parameters is '
  TODO: This might need to be a complex union type, given the different requirements based on the 'in' property. http://swagger.io/specification/#parameterObject
';