First you should know that, we cannot say the db operation will not take much time. you consider the case like, when the db lock happened during that time, if your Insert operation performed then, that will take sufficient amount of time.

when the DB operation takes place, That is a separate process for your perl script. by the time, if parent raises alarm signal, then, the forked process will become orphan. that is the reason a big messup will happen.

To handle this situation, please maintain a flag and keeps track of all the operations performed by your script.