Re: [libreoffice-users] definition of flat/relational database

On 03/03/2013 09:30 AM, Regina Henschel wrote:
> Hi John,
>
> John R. Sowden schrieb:
> > Why do the Libreoffice powers that be define dbase/xbase as  a flat file
> > database, not a relational database.  The below definitions from the
> > Base Intro documentation demonstrate what I am saying:
>
> Do you have a direct link?
>
> > *Flat databases*
> >
> > A flat database contains one or more tables, each containing one or more
> > fields. Each table is completely independent of all the other tables in
> > the database. For example, I have an address database with seven tables
> > in it. One has my family's contacts, another has my business contacts,
> > and another has my wife's family contacts. While some contacts are
> > contained in more than one table, different tables may not have the same
> > information about the same person.
> >
> > dBase is a flat database program. LibreOffice and several database
> > programs can also create flat databases.
> >
> > *Relational databases*
> >
> > Relational databases contain one or more tables with one or more
> > relationships; each relaltionship is defined by a pair of fields. One
> > field of each pair belongs to one table and the second field belongs to
> > the same or a different table. Where relationships exist between fields
> > in the same or different tables, a flat database could still be used,
> > but it provides no mechanism for defining the relationship. Instead the
> > same data must be entered in both fields, making data entry errors more
> > likely. A well designed relational database requires the data to be
> > entered only once, reducing possible errors.
>
> I think, it is a wrong definition of the term 'relational database'. 
> The word 'relation' in 'relational database' means the mathematical 
> definition of 'relation', which is connected to 'tupel', a 
> organization of data in rows and columns. It is not about a 
> 'relationship'.
>
> Another database model is a hierarchical model for example, which is 
> tree-like.
>
> http://en.wikipedia.org/wiki/Relational_database.
> http://en.wikipedia.org/wiki/Database_model
> http://de.wikipedia.org/wiki/Datenbankmodell
>
> It seems, that 'Flat database' is used for a database with one single 
> table. But such a database would still be a relational database. My 
> German text book does not have any term which would correspond to 
> 'Flat database'. And the German Wikipedia article has no database 
> model 'Flat database'.
>
> > dbase is a relational database per the above definition.  I link 2
> > tables with 1 field so I can refer to data in the second database so
> > data does not have to bbe entered multiple times.  In our alarm
> > monitoring station, when a police dept. changes its phone number, we
> > change 1 field in 1 database.  Hundreds of subscriber records refer to
> > that field to populate the data screen.  It seems that LO ptb either
> > have a problem with dbase/xbase, or they are (were) uninformed of the
> > facts.
>
> dBase is a relational database application because the data is 
> organized in tables.
>
> I think, there is no need to introduce the term 'flat database' at 
> all. The distinction is in the management system. For files in 
> dBase-format and for spreadsheets, LibreOffice itself is the database 
> management system. For all other database connections, it uses an 
> external database management system.
>
> Kind regards
> Regina
Direct Link: 
https://wiki.documentfoundation.org/Documentation/Publications#LibreOffice_Base_Guide

A spreadsheet is organized as a table.  That does not make it a 
relational database.

John



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