oracle查询所有表的记录数SQL

Sql代码  
create or replace function count_rows(table_name in varchar2,   
owner in varchar2 default null)  
return number  
authid current_user  
IS  
   num_rows number;  
   stmt varchar2(2000);  
begin  
   if owner is null then  
      stmt := 'select count(*) from "'||table_name||'"';  
   else  
      stmt := 'select count(*) from "'||owner||'"."'||table_name||'"';  
   end if;  
   execute immediate stmt into num_rows;  
   return num_rows;  
end;  

Sql代码  
select table_name, count_rows(table_name)  nrows from user_tables order by nrows desc