Re: Proper relational database? - Mailing list pgsql-general

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Subject Re: Proper relational database?
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Msg-id 004b01d19dd1$b1a325c0$14e97140$@andl.org
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In response to Re: Proper relational database?  (John R Pierce <pierce@hogranch.com>)
List pgsql-general
Absolutely not. SQL is a (nearly) full implementation of the relational algebra, plus other non-relational stuff. The only thing it really can't handle is a table with no columns! (I have to fake that)

a table with no columns would have no primary key...  doesn't that violate one of the fundamental tenets of the relational model ?

john r pierce, recycling bits in santa cruz

The relational model requires a key, but the key can be empty (no attributes). Such a relation can itself be empty, or it can have a single tuple as its body. The maths requires it, and it works just fine.

Regards

David M Bennett FACS


Andl - A New Database Language - andl.org

 

 

 

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