[Discuss] SQL discussion

[Richard Pieri]

On 1/14/2015 1:53 PM, markw at mohawksoft.com wrote:
> Yes, the language structure was designed to facilitate relational data.

No, and go read Jerry's post from this morning for details.


>> Because SQL is built on two dimensional algebra. Two dimensional math
>> cannot easily encompass three or more dimensions.
>
> That's like saying you can't represent 3 dimensions on a piece of paper.

No, it's not. You can represent 3 or 4 or 8 dimensions on a piece of 
paper. That's not the same as being easy to represent 3 or 4 or 8 
dimensions on a piece of paper.


> Why must you perform "multiple queries?" Its all how you choose to
> structure your data and how you choose to query it.

Precisely. What is the structure of a relational database? A table. A 
2-dimensional table. If you have 3 dimensions of data in a relational 
database system then you have a stack of tables. Standard SQL has 2 axes 
for queries: column and row. There is no way to query along the Z axis 
so you have to iterate your queries through the stack (or subset of the 
stack) of tables then combine and filter the results to get what you want.

Or you can use stored procedures or JOINs, both of which have their own 
sets of portability and scalability issues which I consider myself 
wholly unqualified to discuss since I'm not a DBA and I don't want to be 
one when I grow up. :)

-- 
Rich P.