Не правильный вопрос.
Зависит от типа и количества колонок в таблице. Каждая база по своему хранит те же самые текстовые поля или индексы.
Вот пример сколько весят 5 миллионов строк с текстом, индексом и без
211 мб - просто таблица
287 мб - с текстовым полем
394 мб - с индексом по int полю
545 мб - с индексоп по text полю
virtex_old2=# create table test (id serial, amount numeric, customer numeric);
CREATE TABLE
virtex_old2=# INSERT INTO test(amount,customer) SELECT amount, customer FROM (SELECT generate_series(1,5000000) as id, (random()*10000)::int AS amount, (random()*10000)::int AS customer) as aa;
INSERT 0 5000000
virtex_old2=# SELECT nspname || '.' || relname AS "relation",
virtex_old2-# pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
virtex_old2-# FROM pg_class C
virtex_old2-# LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
virtex_old2-# WHERE nspname NOT IN ('pg_catalog', 'information_schema')
virtex_old2-# AND C.relkind <> 'i'
virtex_old2-# AND nspname !~ '^pg_toast'
virtex_old2-# AND relname = 'test';
relation | total_size
-------------+------------
public.test | 211 MB
(1 row)
virtex_old2=# ALTER TABLE test
ADD COLUMN comment text NOT NULL DEFAULT 'text is here';
ALTER TABLE
virtex_old2=#
virtex_old2=# SELECT nspname || '.' || relname AS "relation",
pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
FROM pg_class C
LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE nspname NOT IN ('pg_catalog', 'information_schema')
AND C.relkind <> 'i'
AND nspname !~ '^pg_toast'
AND relname = 'test';
relation | total_size
-------------+------------
public.test | 287 MB
virtex_old2=# CREATE INDEX ON test (customer);
CREATE INDEX
virtex_old2=# SELECT nspname || '.' || relname AS "relation",
pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
FROM pg_class C
LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE nspname NOT IN ('pg_catalog', 'information_schema')
AND C.relkind <> 'i'
AND nspname !~ '^pg_toast'
AND relname = 'test';
relation | total_size
-------------+------------
public.test | 394 MB
(1 row)
virtex_old2=# CREATE INDEX ON test (comment);
CREATE INDEX
virtex_old2=# SELECT nspname || '.' || relname AS "relation",
pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
FROM pg_class C
LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
WHERE nspname NOT IN ('pg_catalog', 'information_schema')
AND C.relkind <> 'i'
AND nspname !~ '^pg_toast'
AND relname = 'test';
relation | total_size
-------------+------------
public.test | 545 MB
(1 row)
