How many columns are too many for a SQL Server 2005 table?

Question

I have a request to allow a dynamic table to have 1000 columns(randomly selected by my end users). This seems like a bad idea to me. It\'s a customizable table so it will

Answer 1

As a rule: the wider the table the slower the performance. Many thin tables are preferable to one fat mess of a table.

If your table is that wide it's almost certainly a design issue. There's no real rule on how many is preferable, I've never really come across tables with more than 20 columns in the real world. Just group by relation. It's a RDBMS after all.