Partitionering weergeven in Postgres 12

Ik weet niet waar je die syntaxis hebt gevonden, duidelijk niet in de handleiding . Zoals je kunt zien daar partities worden gemaakt met behulp van create table .. as partition of in Postgres:

Definieer de tabel:

CREATE TABLE countrymeasurements
(
  countrycode int NOT NULL,
  countryname character varying(30) NOT NULL,
  languagename character varying (30) NOT NULL,
  daysofoperation character varying(30) NOT NULL,
  salesparts    bigint,
  replaceparts  bigint
)
PARTITION BY LIST(countrycode);

Definieer de partities:

create table india 
  partition of countrymeasurements 
  for values in (1);
  
create table japan
  partition of countrymeasurements 
  for values in (2);
  
create table china
  partition of countrymeasurements 
  for values in (3);

create table malaysia
  partition of countrymeasurements 
  for values in (4);