Assume my query will join multiple tables. (Thanks for suggestion about ANSI JOIN and conventional JOIN, but that is not my point here).
SELECT
*
FROM
TableA,
TableB,
(SELECT * FROM TableC WHERE TableC.department != 'R&D') as TableC
WHERE
TableA.user = TableB.user
AND TableA.user = TableC.user
I want to quickly get any 10 rows (top, or random) to preview if the table is what I want. Other than
SELECT
*
FROM
(SELECT
*
FROM
TableA,
TableB,
(SELECT * FROM TableC WHERE TableC.department != 'R&D') as TableC
WHERE
TableA.user = TableB.user
AND TableA.user = TableC.user)
WHERE ROWNUM <=10
what will be the most effective and efficient way to quickly get the preview rows, that not necessary wait for the subquery to finish.