Reply to Re: sequence of columns and preformance

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Posted by Greg D. Moore \(Strider\) on 07/06/06 07:38

"R.A.M." <r_ahimsa_m@poczta.onet.pl> wrote in message
news:rcbpa2d4st31kod14pvig3dihkiockuv6r@4ax.com...
> Hello,
> I am learning SQL Server and I would like to ask you a question. Could
> you tell me please if sequence of columns in a table has influence on
> performance?

Not sure what you mean?

But I'm sorta guessing you're making an assumption which is wrong.

A table itself has no inherent order.

So if you insert 5 rows, there's no guarantee a select statement will return
them in the same order you inserted them.

If you want an order, you must have an order by clause in your statement.

If you want to increase performance of queries, you will want to use
indexes. This keeps track of the "order" of the columns in question. But
doesn't really provide a "sequence."


> Thank you very much
> /RAM/

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