What is the best way to update column1 value from record containing max(column2)?

I came up with this solution:

UPDATE sessions
SET time_stop = now()
WHERE time_start = (SELECT max(time_start) FROM sessions);

开发者_JAVA百科However, I have the feeling that it is not the optimal way of doing it. I would be interested in other, better ways of achieving the same result.

Thank you.

PS: if you feel there is no better way, please say so too.

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I hardly see a way to optimize this query apart from setting up an index on sessions.time_start.