View file vendor/laravel/framework/src/Illuminate/Database/Concerns/ExplainsQueries.php
<?php namespace Illuminate\Database\Concerns; use Illuminate\Support\Collection; trait ExplainsQueries { /** * Explains the query. * * @return \Illuminate\Support\Collection */ public function explain() { $sql = $this->toSql(); $bindings = $this->getBindings(); $explanation = $this->getConnection()->select('EXPLAIN '.$sql, $bindings); return new Collection($explanation); } }