/**
* Order sort groups by increasing totalOutputTupleSize. This minimizes the total volume of data
* that needs to be sorted.
*/
public void orderSortGroups() {
Collections.sort(
sortGroups,
new Comparator<SortGroup>() {
public int compare(SortGroup sg1, SortGroup sg2) {
Preconditions.checkState(sg1.totalOutputTupleSize > 0);
Preconditions.checkState(sg2.totalOutputTupleSize > 0);
int diff = sg1.totalOutputTupleSize - sg2.totalOutputTupleSize;
return (diff < 0 ? -1 : (diff > 0 ? 1 : 0));
}
});
for (SortGroup sortGroup : sortGroups) {
sortGroup.orderWindowGroups();
}
}
