Whenever you feel the need to cut and paste a block of code, it's generally a better idea to turn that block of code into a subroutine.

Further, when reporting an error, it's good to report as much relevant information as possible. Rather than saying

die "Could not open connection to DSN because of [$!]";
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you'd be able to say

die "Could not open connection to $DSN_parameter because of [$!]";
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