title: Search - How to implement the Google website search like the one used here
body: <p>I would like to implement a search function for my website as the functions listed here</p>
  
  <p><a href="https://stackoverflow.com/search">https://stackoverflow.com/search</a></p>
  
  <p>What should I do in order to do this?</p>
  
  <p>Based on my understanding, two methods can be used to provide search function for my website.</p>
  
  <p>1> MySQL full text search
  2> Use search lucene package.</p>
  
  <p>My guess is that the search function here
  <a href="https://stackoverflow.com/search">https://stackoverflow.com/search</a> is neither of them. So what is the method that has been used to provide such a search on the website?</p>
  
  <p>Thank you</p>