code: public function purgeSearchTables()
  	{
  		$objDatabase = Database::getInstance();
  
  		// Truncate the tables
  		$objDatabase->execute("TRUNCATE TABLE tl_search");
  		$objDatabase->execute("TRUNCATE TABLE tl_search_index");
  
  		$strCachePath = StringUtil::stripRootDir(System::getContainer()->getParameter('kernel.cache_dir'));
  
  		// Purge the cache folder
  		$objFolder = new Folder($strCachePath . '/contao/search');
  		$objFolder->purge();
  
  		// Add a log entry
  		$this->log('Purged the search tables', __METHOD__, TL_CRON);
  	}
docs: Purge the search tables