Google Autocomplete - immense speed, no delay

Google recently implemented their "Instant" search facility, with results showing as quick as 0.07 seconds. This surely cannot be done with your everyday jQuery AJAX? What methods are Google using to deploy such a quick, slick autocomplete fe开发者_JS百科ature which crawls and search billions upon billions of web pages in milliseconds?

This question has already been answered here.
It's predictive. The search results are from the first autocomplete suggestion (or the selected one if you hit the down arrow or mouse over a suggestion).