SELECT
 TABLE_NAME,
 to_number(
 extractvalue(
    xmltype(
       dbms_xmlgen.getxml('select count(*) c from '||TABLE_NAME))
  ,'/ROWSET/ROW/C')) COUNT
FROM 
 user_tables
ORDER BY 
 TABLE_NAME;

SELECT owner, TABLE_NAME, 
'select count(*) from '||TABLE_NAME||';' 
FROM dba_tables 
WHERE owner = 'DB_DESIGNER';

SELECT
 TABLE_NAME,
 num_rows counter
FROM
 dba_tables
WHERE
 owner = 'XXX'
ORDER BY
 TABLE_NAME;