In order to speed up searching, you don't search the live database, you search an "index". We create that index through an independent process. This is just like how it works on Google. If you make a change on a website, the changed content isn't instantly available on Google. Google has to crawl and index the changed web page.
We used to update our index just once a day. Two years ago we developed a complex system for dynamic updating. Updates shouldn't take more than 15 minutes now.