Not enough memory - MySQL query in Laravel

For some reason, for a simple mysql query, I do not have enough memory. I must have an error in my request.

Model:

$groups = DB::table('group')
      ->join('organisation', 'group.oid', '=', 'organisation.oid');
    if(Input::get('search')){
      $groups->where('group.group_name', 'LIKE', '%'.$search.'%')
    }
    if($oid!='0'){
        $groups->where('group.oid', '=', $oid);
     }
      $groups->offset($limit)
      ->limit(30)
      ->get();
return $groups;

Error:

Allowed memory size of 134217728 bytes exhausted (tried to allocate 67112960 bytes)

via Chebli Mohamed