Google announced Google Instant on their official blog.
Google Instant - "Search at the speed of thought". Google Instant is results as you type with a new AJAX view of Google's search results. It takes the autocomplete feature a step further and sends the most probable search to the server to fetch the results. A few optimizations to make it possible:
- Prioritizing searches - the biggest optimization is to run only the most probable searches.
- User state - shortcut in process searches that are obsolete to avoid running all searches to completion
- Result caches - improved result caching
Overall, Google claims that instant search saves 2-5 seconds per query. It took some really committed engineers at Google, including Ben Gomes, to make it possible. Kudos!
It is worth noting that many of these ideas have been in the community for awhile. For example, it reminds me of the CompleteSearch system, which has been around since SIGIR 2006. CompleteSearch has some novel prefix based search capability which is still beyond what Google rolled out today.