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From "Amir Michail" <amich...@gmail.com>
Subject Re: Most efficient way to get max row id?
Date Mon, 20 Oct 2008 04:18:38 GMT
On Mon, Oct 20, 2008 at 12:15 AM, Amir Michail <amichail@gmail.com> wrote:
> On Sun, Oct 19, 2008 at 11:25 PM, Kai Ponte <kai@perfectreign.com> wrote:
>> On Sunday 19 October 2008 02:04:29 pm Amir Michail wrote:
>>> On Sun, Oct 19, 2008 at 5:00 PM, Peter Ondruška
>>>
>>> <peter.ondruska@gmail.com> wrote:
>>> > You want to use identity: Defining an identity column
>>>
>>> Yes, but how do you get the max row id efficiently without adding another
>>> row?
>>
>> In the particular table, how many rows are you referring to? A few thousand? A
>> few million?  A hundred million?
>>
>> Do you have an index on the identity column?  What's your datatype?
>
> ~60,000 rows

But there's also a where in the query, so the number of rows
considered by max will vary.  A slow case involves ~ 16000 rows.

Amir

>
> So if I put an index on the identity column, max will be fast?
>
> Amir
>
>>
>> --
>> kai
>> www.filesite.org || www.perfectreign.com
>>
>>
>> Clean out a corner of your mind and creativity will instantly fill it. - Dee
>> Hock
>>
>
>
>
> --
> http://chatbotgame.com
> http://numbrosia.com
> http://twitter.com/amichail
>



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