Thank you. I was just looking at this stackoverflow thread which made me think of the change.
http://stackoverflow.com/questions/11787797/should-every-user-table-have-a-clustered-indexAnd I would like to find out where and how the performance will suffer.
>Clustered indeces are not a panacea. You have to understand how they work or performance suffers. A lot.
>
>
>>I am testing various scenarios of making SQL Select last 100 (top 100 order desc) records executing faster. The current PK constraint (on ORDER_NO) is non-clustered. I change it (in SSMS) from non-clustered to clustered. It took a little time (I understand that all non-clustered indexes have to be rebuilt). Now SQL Select works much faster and execution plan shows that the PK clustered index is used about 99%.
>>All seems to be good.
>>
>>Two question:
>>1. Why by default when I was creating the PK (a while ago) SQL Server created non-clustered?
>>2. What are the downsides of making this PK clustered? It is an order number assigned and is never changed.
>>
>>TIA
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