我们可以在这里使用ROW_NUMBER()：

WITH cte AS (
    SELECT t.*, ROW_NUMBER() OVER (PARTITION BY PK1, PK2 ORDER BY timestamp DESC) rn
    FROM yourTable t
)

SELECT PK1, PK2, value1, value2
FROM cte
WHERE rn = 1;

除了蒂姆斯的回答，似乎GROUP BY也能做到这一点

SELECT t1.* FROM youtable t1
JOIN
 (SELECT MIN(timestamp) as minTimestamp,User FROM yourtable GROUP BY User) t2
ON t1.User=t2.User AND t1.timestamp = t2.minTimestamp
ORDER BY t1.User

另一种选择是使用PostgreSQL的专有distinct on ()

select distinct on ("User") *
from the_table
order by "User", "timestamp" desc;