Most web apps generate a long hex number and use it as a sessionid.
My idea is to create an ID which is auto-incrementing for each generated session and assign it a random secure string (a password). Why? It is easier to look up on an int index, it is faster to update and it occupies less space.
Does this present any security risks? (I ask exclusively for the (int)id-password style; for the string generator I am pretty sure I nailed it)