11 ms·

What are you talking about? A table has as many columns as the thing it describes has attributes to be described. You can have a fully normalized database wit

What are you talking about? A table has as many columns as the thing it describes has attributes to be described. You can have a fully normalized database with 50 column tables in it, and there's nothing unusual or suspect about that.

calpaterson 10y ago
No, relations describe facts, not things. Heath's theorem means you can decompose a table/relation that has n non-key attributes into n tables. This is something you have to do for BCNF. Theoretically it's possible to imagine a normalised relation with 50 columns. In practice a table like that is unusual and suspect (frankly, even in a denormalised design).
- sgeneris 10y ago
  There NO relationships whatsoever between normalization and the number of attributes, which are determined by the number of properties that entities have in the real world i.e., the conceptual model.
  - calpaterson 10y ago
    That is not in conflict with what I said
    - sgeneris 10y ago
      No. I just thought the clarification was important.
- MustardTiger 10y ago
  >No, relations describe facts, not things. That is impressively pointless pedantry even for HN, well done. >Theoretically it's possible to imagine a normalised relation with 50 columns Yes, that would be what I said. "You're wrong because exactly what you said is correct!"
  - sgeneris 10y ago
    No, correctness is not pedantry, except for the ignorant. The database facts are axioms and the facts in query results are theorems -- logical inferences from the axioms. If you don't understand that you have no clue what a relational database is and what a RDBMS does. But hey, you're in the majority. Any linking of number of columns to normalization is pure nonsense. The only accurate thing that can be said is that if you split a relation into multiple projections, by definition each will have less attributes than the original relation. But this is a triviality and it says nothing about the number of columns in the projected relations.
    - MustardTiger 10y ago
      >No, correctness is not pedantry Pedantry is though. And that's what that entirely pointless post was. >Any linking of number of columns to normalization is pure nonsense. That's what I said, that's the point. Don't jump in to a thread you can't be bothered to read.
      - sgeneris 10y ago
        Pointless to anybody incapable of getting the point, of which there are too many.
sgeneris 10y ago
Tables are not relations. Relations have attributes, not columns, that represent entity properties. A R-table is a visual shorthand for a relation -- a way to visualize it on some physical medium (paper, screen) and the two should not be confused.

calpaterson 10y ago

No, relations describe facts, not things. Heath's theorem means you can decompose a table/relation that has n non-key attributes into n tables. This is something you have to do for BCNF. Theoretically it's possible to imagine a normalised relation with 50 columns. In practice a table like that is unusual and suspect (frankly, even in a denormalised design).

sgeneris 10y ago
There NO relationships whatsoever between normalization and the number of attributes, which are determined by the number of properties that entities have in the real world i.e., the conceptual model.
- calpaterson 10y ago
  That is not in conflict with what I said
  - sgeneris 10y ago
    No. I just thought the clarification was important.
MustardTiger 10y ago
>No, relations describe facts, not things. That is impressively pointless pedantry even for HN, well done. >Theoretically it's possible to imagine a normalised relation with 50 columns Yes, that would be what I said. "You're wrong because exactly what you said is correct!"
- sgeneris 10y ago
  No, correctness is not pedantry, except for the ignorant. The database facts are axioms and the facts in query results are theorems -- logical inferences from the axioms. If you don't understand that you have no clue what a relational database is and what a RDBMS does. But hey, you're in the majority. Any linking of number of columns to normalization is pure nonsense. The only accurate thing that can be said is that if you split a relation into multiple projections, by definition each will have less attributes than the original relation. But this is a triviality and it says nothing about the number of columns in the projected relations.
  - MustardTiger 10y ago
    >No, correctness is not pedantry Pedantry is though. And that's what that entirely pointless post was. >Any linking of number of columns to normalization is pure nonsense. That's what I said, that's the point. Don't jump in to a thread you can't be bothered to read.
    - sgeneris 10y ago
      Pointless to anybody incapable of getting the point, of which there are too many.

sgeneris 10y ago

Tables are not relations. Relations have attributes, not columns, that represent entity properties. A R-table is a visual shorthand for a relation -- a way to visualize it on some physical medium (paper, screen) and the two should not be confused.