Re: cdt glossary - TABLE

From: Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be>
Date: Tue, 12 Jul 2005 20:54:22 GMT
Message-ID: <26WAe.143381$Ws5.7593191_at_phobos.telenet-ops.be>

Paul wrote:

> mAsterdam wrote:
> 


>>>A *table* consists of a table header and a body. The *table header*


>>>consists of a list of column names that contains each column name at

>>>most once and associates with each column name in that list a certain

>>>type. The *body* is a bag of rows where a *row* is a list of values
>>>that conforms to the table header.
>>
>>The bag you speak of is not a mixed bag.
>>Just the "unorderedness" of bag is crucial here, right?
>>
>>Another thing bugging me is: every representation of
>>a table /has/ order - but the tables we speak about
>>have none - or do we pretend they have none?
>>I would apreciate it if we would have a friendly explanation
>>for that - it confuses anyone when starting to think about
>>tables at first.
>
> You could say the table header is an (unordered) set of column names.

That would be true (well, not exactly, but anyway) in the relational model, but what was under descussion here was the notion of SQL table. That's something different.

• Jan Hidders

Received on Tue Jul 12 2005 - 22:54:22 CEST