 <p>By definition, <code>SELECT</code> without <code>ORDER BY</code> is not deterministic, and implementation dependent. Server can decide to deliver your results in any order it thinks more performant.</p> <p>For example, if you delete some rows and later insert another set of rows, server may reuse that hole to put new data, and this data may be later delivered by SELECT in physical order on disk, not in order of insertion.</p>