title: Are the results deterministic, if I partition SQL SELECT query without ORDER BY?
body: <p>I have SQL SELECT query which returns a lot of rows, and I have to split it into several partitions. Ie, set max results to 10000 and iterate the rows calling the query select time with increasing first result (0, 10000, 20000). All the queries are done in same transaction, and data that my queries are fetching is not changing during the process (other data in those tables can change, though).</p>
  
  <p>Is it ok to use just plain select:</p>
  
  <pre><code>select a from b where...
  </code></pre>
  
  <p>Or do I have to use order by with the select:</p>
  
  <pre><code>select a from b where ... order by c
  </code></pre>
  
  <p>In order to be sure that I will get all the rows? In other word, is it guaranteed that query without order by will always return the rows in the same order?</p>
  
  <p>Adding order by to the query drops performance of the query dramatically.</p>
  
  <p>I'm using Oracle, if that matters.</p>
  
  <p>EDIT: Unfortunately I cannot take advantage of scrollable cursor.</p>