random selection?

How to generate a random selection in oracle??

i do know that in mysql i can use rand().

Hi,

use :

select ...
from sales sample(5) # or from sales sample(5) blocks

the first will sample 5% out of the table whereas the second 4 block randomly.

Good luck.

Hi, thanks for ur reply.

i tried something like this..
select * from product sample(5) blocks where rownum < 10

and also

select * from product sample(5) # where rownum < 10

but it returns nothing. pls advise.

Hi Joyce,

the reason you probably not getting anything is because the table doesn't have statistics. what you need to do is:

analyze table .... compute statistics;

(if the table is large you better off replacing the compute statistics with estimate statistics sample 20 percent).

Let me know if it helped.

Galit.