Using unsigned in MySQL indexes?

Question

MySQL

Is there any performance gain/loss when using the UNSIGNED attribute on primary keys?
And in general, is there any use for UNSIGNED in indexes, other than increasing the range of numbers?

Answer 1

No.

Answer 2

So just "No" without any arguments?
As far as I remember, unsigned int improves the performance of indexes, and there was an article on mysqlperformanceblog.com about this (I can’t find it right now, but here is www.mysqlperformanceblog.com/2008/12/22/high-performance-click-analysis- with-mysql/ for example, there is a topic here, search for unsigned). You can also read their book High Performance Mysql, preferably part 2.