title: Database supporting fast approximate nearest neighbor queries
body: <p>Is there a database that supports fast approximate nearest neighbor queries in high-dimensional vector spaces?</p>
  
  <p>I'm looking for a database that would fit the following use case:</p>
  
  <ul>
  <li>Works for millions of points</li>
  <li>Works for hundreds-thousands of dimensions</li>
  <li>Potentially uses cover trees or locality sensitive hashing for indexing</li>
  </ul>
  
  <p>Does a robust implementation of this exist?</p>