logical logging

Hi I have a question to ask. I am on HP 9.0 O/X with online 5.12 When I changed to /dev/null on the primary drive from /dev/ifmx/1m and then turned off the B logging, then I ran the sql script after long transaction aborted. Once the script was done, I turned the logging back on and changed to /dev/ifmx/1m. My understanding is that the logical log - completed will be lost that are not backed up. If that is correct, how I restore the logical log? Is it too late? What is the best way to do that without turning off the B logging to run a sql script? I understand that the database_name and informix "fill" the logs, right? Thanks in advance for your helpful response. Thuc