title: Sphinx reindexing takes several hours
body: <p>What should I do to speed up Sphinx indexing (using MySQL)?
  Should I use other database, noSQL database?</p>
  
  <p>Note also that delta indexing is fast, only a full reindeinx process is slow.
  Please explain in details. Thx!</p>
  
  <p>UPDATE:
  I'm reindexing over 100.000 items and my thinking-sphinx index definition looks like this</p>
  
  <pre><code>define_index do
      indexes [text, user(:nickname), user(:full_name)]
      has rewrites(:id), :as =&gt; :rewrite_id
      has rewrites(:user_id), :as =&gt; :rewrite_user_id
      has [rewrites(:user_id), user_id], :as =&gt; :user_id_or_rewrites_user_id
      has comments(:user_id), :as =&gt; :comments_user_id
      has simbols(:id), :as =&gt; :simbol_ids
      has followings(:follower_id), :as =&gt; :follower_id
      has follows(:followable_id), :as =&gt; :followable_id
      has created_at, :sortable =&gt; true
      has rewrites_count, :sortable =&gt; true
      has relevance, :sortable =&gt; true
      has user_id
      set_property :delta =&gt; :datetime
    end
  </code></pre>