>In this case, I don't see a lot of queries unless I misunderstand what a hit table is.
>

Take a look at this short blog post

Best Practice: Every table should have a primary key


>>To speed up queries :-)
>>But it takes its price when you insert/delete big amount of data.
>>
>>>Maybe a dumb question but why have a clustered index?
>>>
>>>>>I am looking to see if there could be a way to optimize a delete SQL I have.
>>>>>
>>>>>Basically, I do something like this every 15 minutes:
>>>>>
>>>>>

>>>>>DELETE FROM Hit WHERE AddDate<something
>>>>>

>>>>>
>>>>>As this is executed every 15 minutes, usually, this is executed in a flash. So, all records from the Hit table which are older than the parameter will be removed. The situation is when I run this command on a test server, where this procedure hasn't been executed since a while, the process may take several minutes.
>>>>>
>>>>>Is it because I am working on a date field? If yes, I can do a SQL at first to get the primary key and then remove anything older than that primary key.
>>>>>
>>>>>Or, is it that it is because there are a lot of records? If this is the case, what can I do to optimize?
>>>>
>>>>As I saw from the Execution plat the most part of the operation if for recreating the clustered index.
>>>>Could you try to remove the index first then DELETE and then recreate it?