Oracle: DBMS_STATS.SET_TABLE_STATS

Artificially blow table size up

create table tq84_blown_up (
   id number,
   txt varchar2(500)
);

insert into tq84_blown_up
select
   level,
   dbms_random.string('a', 500)
from
   dual connect by level < 40;


declare
  nofRows pls_integer;
  nofBlks pls_integer;
  avgLen  pls_integer;

begin

   dbms_stats.gather_table_stats(
      ownname =>  user,
      tabname => 'TQ84_BLOWN_UP'
   );

   dbms_stats.get_table_stats(
      ownname =>  user          ,
      tabname => 'TQ84_BLOWN_UP',
      numrows =>  nofRows       ,
      numblks =>  nofBlks       ,
      avgrlen =>  avgLen
   );

   dbms_stats.set_table_stats(
      ownname =>  user           ,
      tabname => 'TQ84_BLOWN_UP' ,
      numrows =>  nofRows * 12345,
      numblks =>  nofBlks * 12345,
      avgrlen =>  avgLen
   );

end;
/

select
   num_rows,
   blocks,
   avg_row_len
from
   user_tables
where
   table_name = 'TQ84_BLOWN_UP';

See also