title: Boost simple SELECT performance of SQLite database
body: <p>I'm using a SQLite database (1GB+) in which there's only one table of stacked financial tick time series. I'm using RSQLite package to connect to the database. My situation is very simple: select a subset of data from one date to the other, e.g. from <code>20140101</code> to <code>20140930</code>. Therefore the query is simple too:</p>
  
  <pre><code>SELECT * FROM DATA WHERE YMD BETWEEN 20140101 AND 20140930
  </code></pre>
  
  <p>The data is stored on a SSD but the reading time looks still slow. Are there some ways or tips to boost the performance of such simple subsetting query?</p>
  
  <p>The database has 14 columns and on automatic index.</p>