8 ms·

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

45 points by taffer 6y ago

amw-zero 6y ago
Read this paper. Then read his book, The Relational Model for Database Management: https://codeblab.com/wp-content/uploads/2009/12/rmdb-codd.pdf 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 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.
- neolog 6y 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-zero 6y 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?
    - SkyMarshal 6y ago
      You might enjoy this letter by Edward Dijkstra on why Americans sometimes don't realize the mathematical basis of programming: https://www.cs.utexas.edu/users/EWD/transcriptions/EWD06xx/EWD611.html https://www.cs.utexas.edu/users/EWD/transcriptions/EWD06xx/E... Excerpt: "The first series of machines —that of the singletons— was mainly developed in the USA shortly after the World War II, while a ruined continental Europe had neither the technology, nor the money, to start building computers: the only thing we could do was thinking about them. Therefore it is not surprising that many US Departments of Computer Science are offsprings of Departments of Electrical Engineering, whereas those in Europe started (later) from Departments of Mathematics (of which they are often still a part). This different heritage still colours the departments, and could provide an acceptable explanation that in the USA Computing Science is viewed more operationally than in Europe."
      - pyuser583 6y ago
        I’m pretty sure it precedes WWII. Compare the work of scientists like Alan Turing with the pre-war work of Claude Shannon/Vannevar Bush. Turing was a mathematician focused on theoretical problems. Shannon and Bush spent several years building analog computers at MIT. I think the difference was the way electronics and telecommunications established themselves as academic disciplines in America. America was training tons of electrical engineers, but surprisingly few mathematicians, as early as the mid 19th century. Look at schools like MIT - what the UK equivalent? Oxbridge is known for Classics, PPE, and Maths. There’s no “institutes of technology.”
        danielheath 6y ago
        > Turing was a mathematician focused on theoretical problems. The famous theoretical problems of fire-control systems for anti-aircraft weapons and wartime code-breaking.
      - amw-zero 6y ago
        That’s such an interesting perspective. I’d expect nothing less of Djikstra!
  - hyperpallium2 6y 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...
pyuser583 6y ago
Didn’t Cobb spend his later years ranting against SQL? Something about how is was a deeply flawed version of his original idea?
- lifepillar 6y 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
deleted 6y ago
[deleted]
dwenzek 6y 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 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?
- lifepillar 6y ago
  I’d say that the reviews you have cited are satirical.
  - lifepillar 6y 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/80/2014/12/reject.pdf https://wp.doc.ic.ac.uk/cairesfe/wp-content/uploads/sites/80...
    - lifepillar 6y ago
      Ok, I've read everything more carefully: those are clearly hypothetical, entertaining reviews. Hints: (1) the link at the beginning; (2) no references to the sources :-)
      - dwenzek 6y ago
        Thank you. This is the article I remember. And yes, I have been fooled. This is a lesson to only cite (and even remember) carefully read articles!

45 points by taffer 6y ago

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

neolog 6y 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-zero 6y 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?
  - SkyMarshal 6y ago
    You might enjoy this letter by Edward Dijkstra on why Americans sometimes don't realize the mathematical basis of programming: https://www.cs.utexas.edu/users/EWD/transcriptions/EWD06xx/EWD611.html https://www.cs.utexas.edu/users/EWD/transcriptions/EWD06xx/E... Excerpt: "The first series of machines —that of the singletons— was mainly developed in the USA shortly after the World War II, while a ruined continental Europe had neither the technology, nor the money, to start building computers: the only thing we could do was thinking about them. Therefore it is not surprising that many US Departments of Computer Science are offsprings of Departments of Electrical Engineering, whereas those in Europe started (later) from Departments of Mathematics (of which they are often still a part). This different heritage still colours the departments, and could provide an acceptable explanation that in the USA Computing Science is viewed more operationally than in Europe."
    - pyuser583 6y ago
      I’m pretty sure it precedes WWII. Compare the work of scientists like Alan Turing with the pre-war work of Claude Shannon/Vannevar Bush. Turing was a mathematician focused on theoretical problems. Shannon and Bush spent several years building analog computers at MIT. I think the difference was the way electronics and telecommunications established themselves as academic disciplines in America. America was training tons of electrical engineers, but surprisingly few mathematicians, as early as the mid 19th century. Look at schools like MIT - what the UK equivalent? Oxbridge is known for Classics, PPE, and Maths. There’s no “institutes of technology.”
      - danielheath 6y ago
        > Turing was a mathematician focused on theoretical problems. The famous theoretical problems of fire-control systems for anti-aircraft weapons and wartime code-breaking.
    - amw-zero 6y ago
      That’s such an interesting perspective. I’d expect nothing less of Djikstra!
- hyperpallium2 6y 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...

pyuser583 6y ago

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

lifepillar 6y 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

deleted 6y ago

[deleted]

dwenzek 6y 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 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?

lifepillar 6y ago
I’d say that the reviews you have cited are satirical.
- lifepillar 6y 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/80/2014/12/reject.pdf https://wp.doc.ic.ac.uk/cairesfe/wp-content/uploads/sites/80...
  - lifepillar 6y ago
    Ok, I've read everything more carefully: those are clearly hypothetical, entertaining reviews. Hints: (1) the link at the beginning; (2) no references to the sources :-)
    - dwenzek 6y ago
      Thank you. This is the article I remember. And yes, I have been fooled. This is a lesson to only cite (and even remember) carefully read articles!