# SELECT * FROM a ORDER BY d;
 t | d  
---+----
 O |  1
 O |  2
 O |  3
 M |  4
 M |  5
 M |  6
 M |  7
 O |  8
 O |  9
 O | 10
 I | 11
 I | 12
 I | 13
(13 ROWS)