I'm creating a rather complex plugin that synchronizes posts from your server with a thirdparty server. I need to know, if you migrate your wordpress server to a new site, "can" the post ids change? If so is there another unique id?
Also, is there any other instance where a post id could change?
If the id does change and there is no other unique id then chances are I'll just do some complex md5 signature checking and string comparison if need be.