A Relational Model of Data for Large Shared Data Banks (1970) [pdf]

https://www.seas.upenn.edu/~zives/03f/cis550/codd.pdf

by taffer • 6 years ago

45 20 6 years ago

seas.upenn.edu

amw-zero5• 6 years ago

Read this paper. Then read his book, The Relational Model for Database Management: https://codeblab.com/wp-content/uploads/2009/12/rmdb-codd.pd....

It’s mind boggling how much he anticipated about data management, and was absolutely accurate about. As someone who unfortunately learned databases via ORMs, I started to dive into his writing directly and learn more about the relational model itself.

It’s amazing how much power is in the model that I was completely unaware of, like domains: https://www.postgresql.org/docs/9.5/sql-createdomain.html.

It also inspired me to learn more about math, specifically set theory. Set theory is the most practically useful math you can learn as a programmer. It’s a shame that it’s not common to communicate in terms of set theory more at work, considering how much we intuitively use it. You can’t work in a complicated data model without talking about unions, and the relational model itself is just an extension of set theory, very clearly defined via set theory.

It’s funny. Almost every popular tool or technique we use has a clear and direct lineage from math, yet we have a huge anti-math sentiment in our industry at large. I mean. It’s not funny. It’s tragically ignorant.

neolog2• 6 years ago

Almost every popular tool or technique we use has a clear and direct lineage from math

I don't think that's true. It's very often the other way around.

amw-zero5• 6 years ago

My example was the relational model of data, which is literally a mathematical model of data storage.

Other ones I can think of off the top of my head:

- the DOM (an applied tree which is a graph)

- everything to do with programming language construction (compilers and interpreters use graph theory extensively)

- testing (permutations and combinations)

- static analysis (including eslint)

- abstracting logic with functions

Can you think of anything that isn’t directly derived from some math concept?

hyperpallium2• 6 years ago

Apart from relational algebra, two big ones are regular expressions and diff (longest common subsequence).

However, you're saying vice versa: Almost all math we use has a clear and direct lineage from a popular tool or technique.

There's something to this - many of the well-known theorems and algorithms for regular expressions started with Ken Thompson, though of course he used Kleene algebra.

And for relational algebra in this submission, there's almost no mathematics, just a set of tuples... and make an algebra around it. That's why Codd's paper has hardly any references, he pretty much made it all up, to solve a practical problems he saw (unnecessary rewriting of code). Though he was a mathematician, so...

The limits of knowledge, of what can be proven, is to do with "computability" - sure sounds like a prpgrammer thing!

So maybe you have something there...

pyuser5832• 6 years ago

Didn’t Cobb spend his later years ranting against SQL? Something about how is was a deeply flawed version of his original idea?

lifepillar4• 6 years ago

Codd (rightly) recognized two “fatal flaws” [0] in SQL: (1) permitting duplicate rows, and (2) the treatment of missing information (he also criticized the “inadequately defined kind of nesting of a query within a query”, but that addressed 80’s SQL, and I don’t think his criticisms still apply to SQL:2019).

Perhaps ironically, SQL NULLs are modelled directly after his (logically flawed) 1975/1979 proposal [1]. It must be noted, however, that he explicitly considered his proposal “as preliminary and in need of further research”. NULLs in databases are best avoided, or restricted to views (not base tables) and managed with great care (I’d say that they should be used only with the “inapplicable value” semantics [2]).

[0] Fatal Flaws in SQL, Part One and Two, 1988

[1] Extending the Database Relational Model to Capture More Meaning, 1979

[2] Franconi and Tessaris, On the Logic of SQL NULLs, 2012

dwenzek2• 6 years ago

What is really amazing is that this paper has been rejected in the first place (among others).

http://www.fang.ece.ufl.edu/reject.html

I once read this story in either ACM or IEEE but failed to find the exact reference. It was an editorial relating famous papers rejected by the journal. Does anyone have this reference?

lifepillar4• 6 years ago

I’d say that the reviews you have cited are satirical.

lifepillar4• 6 years ago

I retract my assessment. I have found what appears to be the original paper ([0], from Computer 2005), and there is no indication that the reviews are fake. On the contrary, it appears that they are brought up as striking examples of a reviewer's incompetence. Wow!

[0] https://wp.doc.ic.ac.uk/cairesfe/wp-content/uploads/sites/80...

A Relational Model of Data for Large Shared Data Banks (1970) [pdf]

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