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which is efficient count(*) or count(1) ?

 
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Ritesh Chopra

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Joined: 15 Oct 2007
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Location: India

PostPosted: Mon Nov 05, 2007 11:19 am    Post subject: which is efficient count(*) or count(1) ?
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Hi ALL,
please can anybody give me the comparison for count(*) and count(1) in terms of efficiency ? please include a detailed view on how to decide in which situation what is better.
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vasanthkumarhb

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Joined: 06 Sep 2007
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PostPosted: Mon Nov 05, 2007 11:32 am    Post subject:
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Hi,


As i seen both returns the same answer , but if you want to improve the efficiency you need to have proper CLUSTER INDEX in the query.




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Vasanth...... icon_smile.gif
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vasanthkumarhb

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PostPosted: Mon Nov 05, 2007 11:35 am    Post subject:
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Hi,

Adding to the above answer.

I think of count(*) as counting the number of rows but I have heard people liking count(1) as meaning count where the existence of the row is true (1 meaning true).

I think count(1) gives lesser performance over count(*).


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Ritesh Chopra

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PostPosted: Mon Nov 05, 2007 11:41 am    Post subject:
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Thanks but can you explain that in more detail.
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vasanthkumarhb

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PostPosted: Mon Nov 05, 2007 12:47 pm    Post subject:
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Hi Ritesh,

pls find the link below, it is explained practically, it would helpfull for you.


http://justoracle.blogspot.com/2006/12/count-vs-count1.html


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Vasanth......... icon_smile.gif

"Never Give Up Until U Succeed"
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Ritesh Chopra

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Joined: 15 Oct 2007
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Location: India

PostPosted: Mon Nov 05, 2007 4:14 pm    Post subject:
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vasanthkumarhb wrote:
Hi Ritesh,

pls find the link below, it is explained practically, it would helpfull for you.


http://justoracle.blogspot.com/2006/12/count-vs-count1.html


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Vasanth......... icon_smile.gif

"Never Give Up Until U Succeed"


Yap the link has enough details.
Thanks Vasanth.
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