protected function collectGarbage()
 {
     $table = new PhabricatorSystemDestructionLog();
     $conn_w = $table->establishConnection('w');
     queryfx($conn_w, 'DELETE FROM %T WHERE epoch < %d LIMIT 100', $table->getTableName(), $this->getGarbageEpoch());
     return $conn_w->getAffectedRows() == 100;
 }
 public function collectGarbage()
 {
     $ttl = phutil_units('90 days in seconds');
     $table = new PhabricatorSystemDestructionLog();
     $conn_w = $table->establishConnection('w');
     queryfx($conn_w, 'DELETE FROM %T WHERE epoch < %d LIMIT 100', $table->getTableName(), time() - $ttl);
     return $conn_w->getAffectedRows() == 100;
 }