If you have heard that San Jose International is too small to support Boeing 747s (or 777s for that matter), that information is completely false. There were two of them at the airport last week. The military charters 747s out of SJC twice a year, and in the cases of extremely bad weather at SFO they are sometimes rerouted to the airport as well.
However, just because SJC supports these planes doesn't mean we necessarily want them. They generate a lot more noise than smaller planes, especially the fancy new 787s that are being used for international flights to Tokyo and soon Beijing.
Source: The Merc, photo by LiPo Ching