Chris BONDE wrote:
Reply from Chris:
Most of my flat file experience can be easily done with a spread sheet.
My top down or hierarical (sp?) database experience was with a Main
Frame database.
My experience with a relationalship d base was/is not.
I havenot found ( does not mean that there is not) an article that
explains the difference amongst the three. But most importantly when
would use such over another. I think that an explanation on that
would be welcomed.
I did a quick search on Google for "Flat file vs Rlational" and found
these (amongst many):
http://pubs.usgs.gov/prof/p1634j/html/fm_struc.htm
http://www.databasedev.co.uk/flatfile-vs-rdbms.html
and this very concise explanation
http://expertanswercenter.techtarget.com/eac/knowledgebaseAnswer/0,295199,sid63_gci976564,00.html
None however do a good job of saying: Why one or the other for a
specific task? A number of the articles found however do talk about why
a particular project changed from one to the other, so in a way they do
point in this direction. On the other hand though it is a bit of mute
point, if someone creates a database using a Relational Database
Management System with one table what do they have? A flat database,
they just don't realize it. If they create a spreadsheet with multiple
data ranges and use of vlookup to relate entries in these ranges what do
they have? They have a relational data base, without benefit of system
supported constraints, but a relational data model none the less. (IMO)
As for hierarchical vs relational, that is a bit dicier. There are
hierarchical databases all around us, we just don't think of them as
such, much any more. An XML file is the most ubiquitous I would suppose.
A database that is XML enabled, however, may be relational.
In the end I suppose it would be nice to have documentation that goes
into these subjects with some depth, but I would be hard pressed to
understand what audience is really being served. For the most part a
person working in Base is not going to be thinking relational vs
hierarchical vs flat, they have made up their mind, I would contend.
They want relational, they may not know why, maybe because a boss told
them to, or because they think they should. Those that wanted a flat
database are most likely using a spreadsheet.
In talking to people at OOOForum what seems to be most missing right now
is a simple grid that shows what capabilities are offered in Base for
the different data connections. For example, that if you choose to use a
dBase (Flat file) connection you give up the ability to join multiple
tables. The same is true with a SpreadSheet as a data connection. In
fact if you use the spreadsheet you also have a read only connection.
There is also a need for a very simple explanation of the relational
model. I have answered the same question - How to create a one to many
relationship? - at least a dozen times, asked in a dozen different ways.
For this I have been directing people to resources on the net that cover
generic information (or MS Access specific), and then showing specific
implementations in Base.
What does this all mean to the discussion at hand? I don't know. My
small tutorial (or How To), was not intended to answer any of these
types of questions. At least not in so many words. The reason I wrote it
was simply because a number of people at the forum had said, one way of
the other - "OK, I opened the Base module...now what do I do?".
Drew
