How can I select the set of rows where each item has the greatest timestamp?

Question

Using Sqlite, I\'d like to fetch the collection of rows each with the greatest timestamp. The table contains the properties of items, which are key-value pairs and timestamp

Answer 1

Tweaking the query found here, I've come up with the following:

SELECT a.* 
FROM Properties AS a 
INNER JOIN (
  SELECT key, MAX(timestamp) AS max_timestamp 
  FROM Properties 
  WHERE thing='watermelon' 
  GROUP BY key) b 
ON a.key = b.key AND a.timestamp = b.max_timestamp 
WHERE thing='watermelon';

Seems to work, though I'd be interested in comments the pros/cons of this query.