Speed up fixes

Hello,

Unfortunately JDBC drivers for PostgreSQL are always in hot spots on
heavy database usage. I've looked through and fixed 2-3 obvious
performance leaks which saves 20-30% CPU usage percents for our
application. If you are interested please review and commit to your
source tree. See attached diff file for version 8.0.316.

Thanks,
  -- Sergei Rogovskiy
Brightech Inc.