On 02/24/2011 06:20 PM, Josh Berkus wrote:
SELECT id_key, time_stamp, value
FROM (
SELECT id_key, time_stamp, value,
row_number()
OVER ( PARTITION BY id_key
ORDER BY time_stamp DESC)
as ranking
FROM thetable
) as filtered_table
WHERE ranking = 1
Why did you use row_number instead of rank?
I am now curious how the speed compares though. I still think the
DISTINCT ON will be faster, but it would be a great surprise.
--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@xxxxxxxxx
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