T-SQL Tuesday #131: Data Analogies, or: Explain Databases Like I’m Five!

T-SQL-Tuesday
T-SQL Tuesday

Wake me up when September ends

Green Day

Now I am fully awake and ready to contribute to the latest #TSQL2SDAY. This month’s host is Rob Volk (blog|twitter). Rob’s inspiration from Reddit ELI5 resulted in this great topic.

AND vs OR

Back in the days when I was tutoring math, I had two children who were stuck at the basics of mathematical logic. They could not understand the difference between x AND y and x OR y resulting in either TRUE or FALSE. As a math student that was my first challenge, how to explain that concept to people.

X AND Y or Xandy

The idea, I came up with was a marriage. A marriage between X and Y only exists (TRUE) where X is present (TRUE) AND Y is present (TRUE). If either of them is not present (FALSE) there is no marriage (FALSE).

That example really worked, and they were explaining that to their parents – I guess it was all TRUE.

To see OR not to see

Marriage or date did not really work with the OR, so I have used candles. Asked them to imagine a very, very dark room with two candles A and B. If they light either of the candles or both of them (TRUE) they will see what’s inside the room (TRUE). However, if both candles are off (FALSE) then it is dark in the room (FALSE).

That also worked although I have advised them not to experiment with an open fire in the apartment.

metamia.com

While I was doing some research for the topic I found this page Metaphor Lab. This is an organisation that stays behind the Metaphor Festival and it links to an online database called metamia.com.

METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.

metamia.com

You can find thousands of metaphors and analogies like there. Some of them are like these below.

metamia.com – relational database

A relational database has a couple of analogies there, this one made me giggle:)

A relational database is like a garage that forces you to take your car apart and store the pieces in little drawers

relational database ~ garage by metamia.com

metamia.com – metadata

I like this one, as it kind of applies to both digital and analog worlds in photography.

In today’s digital world, metadata is like the blank back of a printed photo. This digital file that accompanies an image is a “place” to “write” information about the image — who made it, who owns the copyrights, what the image depicts, who is in the image, where it was made, when it was made and even camera settings used to create it. 

metadata ~ back of a printed photo by metamia.com

metamia.com – analogy

Finally, with this one I am going to end this post 🙂

An analogy is like a car. If you take it too far, it breaks down.

analogy ~ car by metamia.com

conclusion

In my experience analogies help a lot as everyone has a different background and might understand things differently. Simply repeating the same definition 5 times over and over will not make it easier to understand. In a worst-case scenario, it will summon the Candyman.

Thank you,
Mikey

2 Comments on "T-SQL Tuesday #131: Data Analogies, or: Explain Databases Like I’m Five!"


  1. I loved the analogies for the AND/OR operators.
    I’ll just add on the same topic, regarding the order of evaluation of logical operators.

    How an expression like the following is evaluated?

    x AND y OR z

    Is it like this?:
    (x AND y) OR (z)

    Or this?:
    (x) AND (y OR z)

    The analogy I like to use for remembering the order of evaluation of logical operators, is that of mathematical addition versus multiplication:

    AND is Multiplication (*),
    OR is Addition (+).

    So the expression above would be analogous to:

    x * y + z

    Which is the same as:

    (x*y) + (z)

    And so the answer is:

    (x AND y) OR (z)

    Reply

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