title: What does parsing a query mean?
body: <p>Most relational databases handles a JDBC / SQL query in four steps:  </p>
  
  <ol>
  <li>Parse the incoming SQL query  </li>
  <li>Compile the SQL query  </li>
  <li>Plan/optimize the data acquisition path  </li>
  <li>Execute the optimized query / acquire and return data </li>
  </ol>
  
  <p>I want to know what does "parse the incoming query" really mean? And what does "plan/optimize data acquisition path" mean?</p>