You are writing STDOUT to a logfile, but you should also pipe STDERR to the same logfile. Right now, you probably won't see any error messages generated by this script.
Your script may be failing due to something simple, like the user executing the cronjob doesn't have permission to execute the script. Also, remember that cron executes commands in a very simple environment, and may be very different then your regular interactive shell environment.
Change your script to this:
0 9 * * * /usr/bin/python /home/g1/g1/sphinx/updateall.py > /home/g1/log/updateall.log 2>&1
What does updateall.log show you now?
Also, cron usually logs some information to a logfile. What does /var/log/cron.log say about your cronjob?