2-3 days ago, I came across a code, intended to make delete faster. Just have a look 
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LOOP
SELECT COUNT (1)
INTO v_cnt
FROM table1
WHERE ROWNUM < 2;
IF v_cnt = 0
THEN
EXIT;
END IF;
DELETE FROM table1
WHERE ROWNUM < 1000;
COMMIT;
v_cnt := 0;
END LOOP;
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