@Override
protected List<? extends OperatorFactory> createOperatorFactories()
{
OperatorFactory tableScanOperator = createTableScanOperator(0, "orders", "totalprice", "clerk");
LimitOperatorFactory limitOperator = new LimitOperatorFactory(1, tableScanOperator.getTupleInfos(), ROWS, Optional.<Integer>absent());
OrderByOperatorFactory orderByOperator = new OrderByOperatorFactory(
2,
limitOperator.getTupleInfos(),
new int[] {0},
new int[] {1},
ROWS);
return ImmutableList.of(tableScanOperator, limitOperator, orderByOperator);