/span>      amsterdam z<span class="op">-</span>o     Amsterdam</span>
<span id="cb1-21"><a href="#cb1-21" aria-hidden="true"></a><span class="dv">6</span>     amsterdam z.o.     Amsterdam</span></code></pre></div>
<p>When performing deduplication we will link a dataset to itself and will try to link different records belonging to the same object. When a dataset to itself, it is not necessary to both compare record <em>i</em> to <em>j</em> and <em>j</em> to <em>i</em> and we certainly do not want to compare