I have a table , which contains upto 20 columns. The data is selected, inserted, and deleted by 3 columns: Username, StartDate, and EndDate.
These 3 columns are NOT unique.
The table is a standalone table - no joins to other tables.
Do I create a clustered index on these 3 columns? Or do I create a UniqueID that autoincrements as a PK, and then create a non-clustered index on those 3 columns? Or is a Primary Key required at all?
SELECT StartDate, EndDate, Username, Value1, Value2, Value3, Value4, Value5, Value6 FROM myTbl WHERE Username = @Username AND StartDate = @StartDate AND EndDate = @EndDate; DELETE FROM myTbl WHERE Username = @Username AND StartDate = @StartDate AND EndDate = @EndDate