title: do I need to learn sqldeveloper-specific commands for PL/SQL queries?
body: <p>There are statements like </p>
  
  <pre><code>SET server output ON
  PRINT var_name
  DEFINE var_name
  VARIABLE  var_name
  </code></pre>
  
  <p>etc. which are typed outside the PL/SQL block. These are SQL+ commands which also seem to work on SQlDeveloper, both of which are tools to execute PL/SQL scripts in. Is there any standard that these non-PL/SQL commands follow, i.e. since they are tool-specific, they can differ, say in, SqlDeveloper and SqlPlus. Whose statements should I learn ?</p>