Select a random sample of results from a query result

Question

This question asks about getting a random(ish) sample of records on SQL Server and the answer was to use TABLESAMPLE. Is there an equivalent in Oracle 10?

Answer 1

Something like this should work:

SELECT * 
FROM table_name
WHERE primary_key IN (SELECT primary_key 
                      FROM
                      (
                        SELECT primary_key, SYS.DBMS_RANDOM.RANDOM 
                        FROM table_name 
                        ORDER BY 2
                      )
                      WHERE rownum <= 10 );

Answer 2

SELECT  *
FROM    (
        SELECT  *
        FROM    mytable
        ORDER BY
                dbms_random.value
        )
WHERE rownum <= 1000