}
isFirstKey = false;
Long keyCountObj = parentKeyCounts.get(pos);
long keyCount = (keyCountObj == null) ? -1 : keyCountObj.longValue();
MapJoinTableContainer tableContainer = useOptimizedTables
? new MapJoinBytesTableContainer(hconf, valCtx, keyCount, memUsage)
: new HashMapWrapper(hconf, keyCount);
while (kvReader.next()) {
rowCount++;
lastKey = tableContainer.putRow(keyCtx, (Writable)kvReader.getCurrentKey(),