return 2;
}
@Override
public void prepare() throws Exception{
final TaskConfig config = this.taskContext.getTaskConfig();
// obtain task manager's memory manager and I/O manager
final MemoryManager memoryManager = this.taskContext.getMemoryManager();
final IOManager ioManager = this.taskContext.getIOManager();
// set up memory and I/O parameters
final double fractionAvailableMemory = config.getRelativeMemoryDriver();
final int numPages = memoryManager.computeNumberOfPages(fractionAvailableMemory);
// test minimum memory requirements
final DriverStrategy ls = config.getDriverStrategy();
final MutableObjectIterator<IT1> in1 = this.taskContext.getInput(0);
final MutableObjectIterator<IT2> in2 = this.taskContext.getInput(1);
// get the key positions and types
final TypeSerializer<IT1> serializer1 = this.taskContext.<IT1>getInputSerializer(0).getSerializer();
final TypeSerializer<IT2> serializer2 = this.taskContext.<IT2>getInputSerializer(1).getSerializer();
final TypeComparator<IT1> comparator1 = this.taskContext.getDriverComparator(0);
final TypeComparator<IT2> comparator2 = this.taskContext.getDriverComparator(1);
final TypePairComparatorFactory<IT1, IT2> pairComparatorFactory = config.getPairComparatorFactory(
this.taskContext.getUserCodeClassLoader());
if (pairComparatorFactory == null) {
throw new Exception("Missing pair comparator factory for Match driver");
}