Posted by Alex Kuznetsov on 08/14/07 15:15

On Aug 7, 1:10 pm, Sonny <Sonny...@gmail.com> wrote:
> Hi,
>
> Would like to know the performance differenece between Multi-column
> Index vs Single Column Indexes. Let's say I have a table with col1,
> col2, col3 along with a primary key column and non-indexed columns.
> In queries, I will use col1, col2, and col3 together and some times
> just one or two of these three columns. My questions is, should I
> create one index contains col1, col2, and col3, or create 3 seperated
> columns. I.e. each column has its own index. Any performance
> difference?
>
> Thanks a lot.

It depends on your workload. You need to try it out using the mix of
reads and writes similar to your actual activity.

Alex Kuznetsov, SQL Server MVP
http://sqlserver-tips.blogspot.com/

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