Brian Selzer wrote:
> "Cimode" <cimode_at_hotmail.com> wrote in message
> news:1178044184.315215.167590_at_p77g2000hsh.googlegroups.com...
>> What is a *database value* ? What do you mean that a database
>> (collection of facts) is one single value? Do you mean a relation
>> value? (the database being perceived as one single complex relation?)
>>
>
> The term "database" is pretty loaded. Most of the time a database is a
> value, a set of relations conforming to a particular schema--a
> representation of a collection of facts at a particular instant. In the
> context of modification, on the other hand, a database is a mutable entity
> whose state transitions from value to value as a result of a series of
> events. I use the phrases "database value" and "database state" to
> forestall any confusion.
>
> A set is a value. A database (in the first sense) is a set of named sets
> (relations) of sets (tuples) of named values (attribute values) that
> conforms to a particular schema. Therefore it is a single value.
Or, if you want to simplify the above by avoiding "state" and "mutable",
you could say (as D&D do) that a database is a variable---a
dbvar---which has a db value. Which is a tuple.
--
Jon
Received on Wed May 02 2007 - 05:18:23 CDT
