SAMPLE(N)?
没有听过过啊
我都是使用的DBMS_RANDOM来做的。------------------------
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| 相逢何必曾相识 |
| |
------------------------
没有听过过啊
我都是使用的DBMS_RANDOM来做的。------------------------
| |
| 相逢何必曾相识 |
| |
------------------------
http://download-west.oracle.com/docs/cd/B10501_01/appdev.920/a96612/d_random.htm#998100
SQL> select * from zyz2;
ID P1 P2
---------- ---------- ----------
1 211 212
2 12 14
4 241 242
2 145
1 11
3 17 26 rows selected.Elapsed: 00:00:00.50
SQL> select id,p1,p2 from (select zyz2.*,dbms_random.random num from zyz2 order
by num) where rownum<3; ID P1 P2
---------- ---------- ----------
2 12 14
1 211 212Elapsed: 00:00:00.30
SQL> select id,p1,p2 from (select zyz2.*,dbms_random.random num from zyz2 order
by num) where rownum<3; ID P1 P2
---------- ---------- ----------
3 17 2
2 12 14Elapsed: 00:00:00.30
select * from (select * from ur_table order by sys_guid()) where rownum<n;
select * from (select * from ur_table order by dbms_random.value) where rownum<n;