Re: Users vs. Schemas

From: DA Morgan <damorgan_at_psoug.org>
Date: Sat, 30 Jun 2007 07:46:27 -0700
Message-ID: <1183214710.789318@bubbleator.drizzle.com>

Serge Rielau wrote:

> DA Morgan wrote:

>> Serge Rielau wrote:
>>> Mark D Powell wrote:
>>>> For explaining the differences between a USER and a SCHEMA to a
>>>> developer looking at the CREATE USER and CREATE SCHEMA command results
>>>> is a good idea.
>>>>
>>>> But is there a consensus of how best to describe PUBLIC?
>>> If one takes a step back, or a couple, things come into focus:
>>> Conceptually schemas and users are unrelated beyond the generic
>>> concept of object ownership, which is a property to most objects
>>> (such as tables).
>>> A schema is best described as a "directory" in a file system
>>
>> Are you still using tape-sort technology too?
>>
>> These may help:
>> http://www.psoug.org/files/files_vs_db.pdf
>> http://www.psoug.org/files/why_databases.pdf
>>
>> > Now you can bring it back to a specific implementation. In this case
>>> Oracle where the mapping between user and schema is 1-0..1.
>>> Hence the confusion. It's like the relationship between mass (gram)
>>> and force (N).
>> I wasn't confused before reading that last paragraph. <g>

> Ignorance is bliss. Perhaps if you actually read the post and reflect on 
> it instead of acting all pavlovian at the first mentioning of the word 
> "file" things come into focus.
> 
> Cheers
> Serge

No matter how many times I read:
"A schema is best described as a "directory" in a file system" I can't find enough chocolate to make it palatable.

I know a lot of people, and many books, have used the file cabinet, file system, analogy to try to explain databases. But I find it very misleading.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org

Received on Sat Jun 30 2007 - 09:46:27 CDT