Historically, I have dealt with the problem of “global DB handles” and other such things simply by defining a package named Global.   This package contains functions which produce the necessary values, if necessary doing so on-demand.   For example, my $dbh = Global::DBHandle;.   (If you need to use more than one database, simply have a separate function to automagically produce each handle.)   You can replace this functionality with stuff to, say, use a DB handle cache, without affecting anything else in the program.   And that is what I consider to be a win:   there is a globally-available yet concretely documented way to obtain the necessary values and handles, and each is a function that returns it.   If anything “has to happen,” here is a central and obvious place to put that.   It is crystal-clear what is being done and why.   This has for a long time been my standard practice.