+----+---------+---------------+--------+------------+
| id | item_id | property_name | value  | timestamp  |
+----+---------+---------------+--------+------------+
|  1 |       1 | color         | blue   | 2018-01-01 |
|  2 |       1 | size          | large  | 2018-01-01 |
|  3 |       1 | weight        | 65     | 2018-01-01 |
<SNIP>
| 15 |       1 | color         | purple | 2018-02-01 |
| 16 |       1 | weight        | 69     | 2018-02-01 |
+----+---------+---------------+--------+------------|

+---------+--------+--------+--------+
| item_id | color  | size   | weight |
+---------+--------+--------+--------+
|       1 | purple | large  | 69     |
+---------+--------+--------+--------+