adds  TODO: **NOW**  for improving codes for opening db/table
Signed-off-by: Sho Nakatani <lay.sakura@gmail.com>
adds script for running unit tests
Signed-off-by: Sho Nakatani <lay.sakura@gmail.com>
removes mem leak when overflow page exists
Signed-off-by: Sho Nakatani <lay.sakura@gmail.com>