Right, and there&#x27;s a huge number of index-assisted ways in which in can be queried, but ltree has some restrictions on what nodes can be called, which can be a problem if you&#x27;re trying to represent hierarchies of nodes that already exist.<p>Most of the operations described in the article are performed by using the &amp;&amp; (overlaps) operator, which can make use of a GIN index (though the article doesn&#x27;t mention this), so probably the article&#x27;s approach will work OK.