public OrderedHashSet getUniqueColumnNameSet() { OrderedHashSet set = new OrderedHashSet(); if (columnAliases != null) { set.addAll(columnAliases); return set; } for (int i = 0; i < rangeTable.columnList.size(); i++) { String name = rangeTable.getColumn(i).getName().name; boolean added = set.add(name); if (!added) { throw Error.error(ErrorCode.X_42578, name); } } return set; }