ular, this occurs when executing queries
     involving large numbers of join operations. In order to determine
     a reasonable (not necessarily optimal) query plan in a reasonable amount
     of time, <span class="productname">PostgreSQL</span> uses a <em class="firstterm">Genetic
     Query Optimizer</em> (see <a class="xref" href="geqo.html" title="Chapter 62. Genetic Query Optimizer">Chapter 62</a>) when the number of joins
     exceeds a threshold (see <a class="xref" href="runtime-config-query.ht