One of the SQL queries I am working on is slow in performance. I have been trying to fix it for the last two days, unsuccessfully. The query is generated from an application (Linq to sql -EFF), and based on the user search criteria, it passes parameters to the query.
I looked into the execution plan and I see sort operations. One of the sort operation is
SORT(DISTINCT). I checked the query and I found some
order by in the query. Removing
order by didn't help, and I dont have a
DISTINCT in the query. On checking the properties of the
SORT(DISTINCT) it is not showing the field on which it is doing sort. I have attached the screenshot of that.
After doing some research I learned that
where conditions can generate
SORT operations as the
MERGE required some kind of sort, and I do have
where conditions which looks like:
where (column1 = @param1) OR (column1 IS NULL) OR (@param1 IS NULL)
Someone suggested me in an earlier post that, this are "Kitchen sink" queries and it will cause performance issues.
Is there anyone who had to deal with similar situation? Any solutions?