@Override
  public Region getRegion() {
    return region.getRegion();
  }
The Iterators for index creation are different then those which are used for index updates as
in case of Index creation the 0th iterator is modified such that it always represents
collection of Region.Entry objects. As a result all the rest of iterators as well as indexed
expression have to be modified to appropriately resolve the dependency on 0th iterator.The
missing link indicates the dependency. The original 0th iterator is evaluated as additional
projection attribute. These changes provide significant improvement in Index creation as
compared to previous method. In this approach the IMQ acts on all the entries of the region
while in previous , it iterated over the individual entry of the Region & applied IMQ to it.
geode-core/src/main/java/org/apache/geode/cache/query/internal/index/FunctionalIndexCreationHelper.java