This example of DSNs is a microcosm of what Rose::DB does on behalf of Rose::DB::Object, namely isolating it from (or providing a uniform set of introspection methods to determine) the differences between the databases.

I'm sorry that you think you are performing a useful service. You've forgotten the point of encapsulation. By breaking that encapsultion of the dsns, you are just complicating the life of your users. And "introspection" without good purpose, is no good reason.

When the postman delivers me a letter, he hands me the envelope. He doesn't read the contents to me, whilst handing juicy details of the sender and contents to my neighbours.

Yes. DBD breaks out parts of the dsn, but that's its job! But it only looks at those parts it needs to find the right DBD::* module. It hands the rest over to that particular DBD::* module untouched. Because only that module knows what to do with them.

Another analogy. Take a close look at TCP/IP packets. The application passes a data block. That gets wqrapped in UDP or TCP headers and gets passed to the IP layer where IP headers get added. And that gets passed to the link layer where frame headers get added. To each of these layers, the packet from the layer above is just an opaque lump. And that's exactly how it should be.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
RIP an inspiration; A true Folk's Guy

In reply to Re^7: Avoiding compound data in software and system design by BrowserUk
in thread Avoiding compound data in software and system design by metaperl

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.