Oracle/Shuffle data

The following statement(s) creates a copy of an existing table (address), randomly shuffles each (selected) column within the temporary table and puts them back into the original table. Afterwards the data within the original table (selected columns only) are randomly shuffled. The individual random min/max values are mandatory since without them all columns (here name and street) would be 'shifted' together (the pair would stay together).

CREATE TABLE address_tmp as SELECT * FROM address;
MERGE INTO address t1
 USING (SELECT address_id,
               nvl(lead(name) over (order by dbms_random.value(1,1)),
                   first_value(name) over (order by dbms_random.value(1,1))) name,
               nvl(lead(street) over (order by dbms_random.value(2,2)),
                   first_value(street) over (order by dbms_random.value(2,2))) street
          FROM address_tmp) t2
    ON (t1.address_id = t2.address_id)
WHEN matched THEN
UPDATE
   SET t1.name = t2.name, t1.street = t2.street;
--drop table address_tmp;

If no temp table is used in the above example, data will (most likely) be lost since the select statement will work a changing table so that some information will be multiplied and some will be lost.