demo read commit transaction isolation level

CREATE TABLE website (
    hits INTEGER
);

INSERT INTO TABLE website (9);
INSERT INTO TABLE website (10);

BEGIN;
UPDATE website SET hits = hits + 1;
-- run from another session; DELETE FROM website WHERE hits = 10;
COMMIT;

The DELETE will have no effect even though there is a website.hits = 10 row before and after the UPDATE. This occurs because the pre-update row value 9 is skipped, and when the UPDATE completes and DELETE obtains a lock, the new row value is no longer 10 but 11, which no longer matches the criteria.

from postgre Read Committed Isolation Level doc error: cannot format -: Cannot parse: 2:14: tags:reference, work,