We don't know that he's necessarily using DBI, and, moreover, The OP was asking for explanation of a snippet he didn't understand. He wasn't asking for advice on how to refactor the code.

Update: Sorry for not reading the whole post. I still think the OP was simply asking for help understanding a snippet of code, and the context wasn't as important, but I should have read the question all the way.

We don't know that he's necessarily using DBI,

We do. He explicitely stated that @rows comes from DBI::fetchrow_array().

He wasn't asking for advice on how to refactor the code.

Maybe not, but the OP's question was answered, and it's tradition to offer alternatives, especially when they are better.