Gazareth (8/30/2012)
Nice question Hugo, thanks.Got 3 of the 4 - knew bitmap indexes were available on other DB software, thought it might have been introduced with 2012.
Thought 260 columns for columnstore indexes was a slightly random number so didn't go for that 🙂
Thanks, Gazareth!
The 260 number is deliberately chosen to exceed 256, 28 or the number of values in a tinyint. This vlaue is a common boundary value in software. (For example, before SQL Server 2008, nonclustered indexes on a table were identified by a tinyint column with two reserved values, leaving room for 254 other values; the actual maximum number was 250 - I think they simply rounded down to a pretty number). So I picked the number 260 to distinguish those who believe in a maximum of 256 columns per columnstore index from those who believe in a larger or no maximum.