I am currently allotting data types to attributes. I would like know the usage of Float visa vis Decimal. Say I have got a field whose maximum holding capacity is Decimal(11,3) which the data may ocassionaly reach. Is it advisable to have float istead of Decimal. Will float have any overhead/benifits in terms of performance and storage. Float, I find is not commonly used in commercial applications.
Is there any overhead on Varchar as an Primary Key.
I would recommend trying to identify a numeric field for your primary key.
From the SQL Server 2000 training course ... "A Primary Key should be a
numeric value if possible, but this is not a hard and fast rule."
I believe this is because character searches will perform slower than numeric searches.
As for the Decimal vs Float ... from books online ...
"Because of the approximate nature of the float and real data types, do not use these data types when exact numeric behavior is required, such as in financial applications, in operations involving rounding, or in equality checks. Instead, use the integer, decimal, money, or smallmoney data types."
So it all depends on what the purpose of the field is. What data are you storing in the numeric field?