Re: Picking out the most recent row using a time stamp column

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@peak6.com

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