This isn't just a Perl issue or even a programming issue. Database work also generates warnings and errors that most developers just ignore. I've gone ahead and fixed warnings on SQL scripts for different databases and ended up fixing both long-standing bugs and bugs they didn't even know they had.

Lesson: Warnings are there for a reason. You shouldn't ignore a warning unless you have researched it and determined that you actually want to do whatever it is that's triggering the warning. THEN, you go ahead and document that this warning is expected and the reason why it's ok. AND THEN, you have another developer sign off on it. Both your names are in that comment forever and ever, amen!

Personally, in over 10 years, I've never run into a situation where a warning was actually warranted. But that's just me.