create table TEST_LC_DATA as
select
	IDX,
	TEST_STRING,
	RANDOM_STRING,
	RANDOM_DATE as NIND_DATE,
	RANDOM_DATE as IND_DATE,
	TO_CHAR(RANDOM_DATE, 'YYYYMMDDHH24MISS') as NIND_DTOS,
	TO_CHAR(RANDOM_DATE, 'YYYYMMDDHH24MISS') as IND_DTOS,
	RANDOM_STR as NIND_CONTENT,
	RANDOM_STR as IND_CONTENT
from
	(
	select
		GS as IDX,
		'테스트 문자열 ' || SUBSTR(MD5(RANDOM()::text),0,5) as TEST_STRING,
		MD5(RANDOM()::text) as RANDOM_STRING,
		TIMESTAMP '2010-01-10 00:00:00' + RANDOM() 
          * (TIMESTAMP '2021-12-31 23:59:59' - TIMESTAMP '2010-01-01 00:00:00') as RANDOM_DATE,
		SUBSTRING('가나다라마바사아자차카파하', TRUNC(RANDOM() * 13)::INTEGER + 1, TRUNC(RANDOM() * 3)::INTEGER + 2) as RANDOM_STR
	from
		GENERATE_SERIES(1, 10000000) as GS ) as TEST_LC_DATA;

generate_series 부분에 만들양을 설정