Я тоже помню, в свое время ломал голову, как решить аналогичную вашей, уважаемый niсk, задачу. Нужно было выводить месяц и кол-во чего-то там за каждый день месяца. И кроме того, что ниже, ничего, увы, в голову не пришло:
SELECT * FROM (
SELECT 1 AS Day FROM DUAL UNION ALL
SELECT 2 AS Day FROM DUAL UNION ALL
SELECT 3 AS Day FROM DUAL UNION ALL
SELECT 4 AS Day FROM DUAL UNION ALL
SELECT 5 AS Day FROM DUAL UNION ALL
SELECT 6 AS Day FROM DUAL UNION ALL
SELECT 7 AS Day FROM DUAL UNION ALL
SELECT 8 AS Day FROM DUAL UNION ALL
SELECT 9 AS Day FROM DUAL UNION ALL
SELECT 10 AS Day FROM DUAL UNION ALL
SELECT 11 AS Day FROM DUAL UNION ALL
SELECT 12 AS Day FROM DUAL UNION ALL
SELECT 13 AS Day FROM DUAL UNION ALL
SELECT 14 AS Day FROM DUAL UNION ALL
SELECT 15 AS Day FROM DUAL UNION ALL
SELECT 16 AS Day FROM DUAL UNION ALL
SELECT 17 AS Day FROM DUAL UNION ALL
SELECT 18 AS Day FROM DUAL UNION ALL
SELECT 19 AS Day FROM DUAL UNION ALL
SELECT 20 AS Day FROM DUAL UNION ALL
SELECT 21 AS Day FROM DUAL UNION ALL
SELECT 22 AS Day FROM DUAL UNION ALL
SELECT 23 AS Day FROM DUAL UNION ALL
SELECT 24 AS Day FROM DUAL UNION ALL
SELECT 25 AS Day FROM DUAL UNION ALL
SELECT 26 AS Day FROM DUAL UNION ALL
SELECT 27 AS Day FROM DUAL UNION ALL
SELECT 28 AS Day FROM DUAL UNION ALL
SELECT 29 AS Day FROM DUAL UNION ALL
SELECT 30 AS Day FROM DUAL UNION ALL
SELECT 31 AS Day FROM DUAL
) A, PblIndaysCounts B
WHERE B.DayID(+)=
TO_NUMBER(TO_CHAR(SYSDATE,'YYYYMM')||DECODE( SIGN(A.Day-10), -1, '0'||A.Day, A.Day))

Ну а почему бы вам не остановиться на вашем же варианте? Ведь с точки отсчета прошло немного-нимало чуть менее 731 тысячи дней. Думаю, такой объем записей из одного столбца ничуть не нагрузит базу.