Changes to improve IUD statement performance

Change Owner: Selvaganesan Govindarajan
Reviewer: Mike Hanlon
Summary of change:
Avoids  intermediate Thrift  objects for IUD statements to improve its
performance.
Changed the default max heap size for java objects to be 512mb

Change-Id: Ib50734f82afcf54c1dec6c182c2f936c3de1c18a
Merge "Changes to improve IUD statement performance"