Is there is any Performance issue while using ISNULL() in SQL Server?

Question

I am using ISNULL in MS SQl server 2008, since my table is too huge, whether using of ISNULL may cause any thing to the performance ?.

Than

Answer 1

If you need to use it, then any differences between ISNULL and alternatives like COALESCE or CASE are minuscule. Don't worry about it

Any differences come from how datatypes are handled. COALESCE/CASE can add implicit data type conversions whereas ISNULL has simpler rules.

Edit

ISNULL in the SELECT list to suppress NULLS is trivial. The main work will done in processing rows and data. An extra ISNULL won't be measurable: Don't optimise prematurely