Mini porównanie - ktoś może wytłumaczy mi...

CREATE TABLE operators
(
  id serial NOT NULL,
  nazwa character varying(64),
  CONSTRAINT operators_pkey PRIMARY KEY (id)
)
WITH (
  OIDS=FALSE
);
ALTER TABLE operators OWNER TO mik;

CREATE TABLE groups
(
  id serial NOT NULL,
  parent_id integer,
  nazwa character varying(64),
  CONSTRAINT groups_pkey PRIMARY KEY (id)
)
WITH (
  OIDS=FALSE
);
ALTER TABLE groups OWNER TO mik;

CREATE TABLE elements
(
  id serial NOT NULL,
  parent_group integer,
  nazwa character varying(64),
  CONSTRAINT elements_pkey PRIMARY KEY (id)
)
WITH (
  OIDS=FALSE
);
ALTER TABLE elements OWNER TO mik;

CREATE TABLE payment
(
  id serial NOT NULL,
  child_id integer,
  ma integer DEFAULT 0,
  winien smallint DEFAULT 0,
  rocznik smallint,
  CONSTRAINT primary_key PRIMARY KEY (id)
)
WITH (
  OIDS=FALSE
);
ALTER TABLE payment OWNER TO mik;

-- Index: "Rocznik"

-- DROP INDEX "Rocznik";

CREATE INDEX "Rocznik"
  ON payment
  USING btree
  (rocznik);