"Supported" is always a touchy subject. I am pretty sure that there's nothing in the documentation that says you can't do what you want but to Gene's point, once you do, it will always create the question and possibility that what you did is the source of future problems.
That said, you leave out the goal of your request. There are a couple probes that are designed out of the box to read files and import them - file_adapter for instance. Your app coulr process the data then drop the requisite file for the file_adapter probe to pick up. Or why not have your perl application put the data on the bus as QoS instead of doing the database inserts yourself?
And again, depending on the data, the nas LUA scripting has the concept of persistent variables that wind up being stored in the local nas database.
-Garin