[Postgresql] Test array update efficiency

populate_table_random_data.sql

CREATE OR REPLACE FUNCTION random_int_array(dim integer, min integer, max integer) RETURNS integer[] AS $BODY$
begin
	return (select array_agg(round(random() * (max - min)) + min) from generate_series (0, dim));
end
$BODY$ LANGUAGE plpgsql;

CREATE EXTENSION pgcrypto;

CREATE TABLE test_table as select id, md5(random()::text) || id as name, random_int_array(500000, 100, 10000) as arr, gen_random_uuid() uid from generate_Series(1,3) id
;

\timing
update test_table set arr=arr[10:array_length(arr,1)];

--- get only last two elements from array
select arr[array_upper(arr, 1) -(2 - 1):array_upper(arr, 1)] from test_table;