I was reading about SharePoint 2010 list and library version history boundaries and found, that the limit is 400'000 (source link from Technet). But I got a bit confused - does this limit refers to one item or to all items combined in list/library?
And other question - if limit is exceeded, what will happen? In article there is said that "basic operations may not succeed", but what it realy means? What "plays the major role" of succeeding or not succeeding - WFE and SQL server horsepower?