String[] colNames1 = index1.getColumnNames();
String[] colNames2 = index2.getColumnNames();
if (ArrayUtil.commonElements(colNames1, colNames2).length == 0) {
// no common columns - this is no change, but a removal and creation
tableChange.addSubChange(new IndexDeletion(index1));
tableChange.addSubChange(new IndexCreation(index2));
} else {
// there are common columns
CompositeStructuralChange<DBIndex> indexChange = new IndexChange(index1);
OrderedListComparator<DBColumn, DBIndex> comparator = new IndexColumnListComparator();
comparator.compareComponents(columns(index1), columns(index2), indexChange);