Re: Universal Astrological Database Format
Date: Mon, 14 Jul 2003 20:32:07 GMT
Message-ID: <MPG.197cdd4e43ac2f0c989689_at_news.easynews.com>
In article <45878464.0307121327.2d14dc78_at_posting.google.com>, you say...
> 1. Isn�t an xml database really a flat file?
No. Not necessarily. The internal physical storage of an XML document does not have to be in XML. I don't know what most XML engines for an XML database use internally.
Also, some databases can do XML, but are better known as relational (actually SQL) databases, such as SQL Server and Oracle.
> 2. If I add an entry to an XML file doesn�t it have to be �inserted�
> in the proper section of the file?
Yes.
> Is this insertion handled by the
> programmer or is there an �engine� that handles reads and writes to
> the file? (Visual Basic uses the Jet DB engine).
For insertion into your own XML files, you need a programmer with the appropriate XML libraries (depending on the system used to implement the software) to make things easier, but it could be done manually if you are a masochist. :)
> If the programmer has
> to handle writes then it seems the entire file has to be rewritten
> every time there is an update.
If you use an XML file to store all app data, then yes. If you use an embedded, or external, XML database engine, then no.
> 3. Are there ODBC dll�s to connect to an xml database?
Depends on the database used.
> 4. Is there an XML editor (preferable free) out there to build tables
> and relationship connections?
Read up on XML Schema. There are no such things as "relationships" and "tables" in XML.
> 5. Can you run SQL queries on an xml file?
Read up on XPath.
> 6. Is XML really the best solution for designing an analytical
> relational database?
No. Without knowing your data and how it all inter-relates, this is a hard call to make. A native XML database might or might not be suitable, irrespective of how you feel on the need for relational purity. If you want to look, there are a lot of free XML-based tools out there to be had in the open-source world. Personally, I wouldn't want to use XML for the data management engine.
However, XML would probably be great as the means to exchange internal data in your app and the other apps you spoke of in your original post. The "universal file format" would be an export/import capability that would be found in some or all astrology prgrams.
> One thing I don�t like about the xml format is the fact that you can
> open it with a word processor.
Ironically, this is often quoted as one of its best features!
> I�m planning this database file to be
> the storage format for a program I intend to write (it won�t be web
> based). It seems the text-based nature of xml makes it more
> �tinkerable�, easily corruptible by someone with good intentions.
Yes, but even a binary file can be "tinkered" and ruined. Harder, and scarier to the newbie, but still possible. The nice thing about an XML file is that it *could* potentially be fixed as easily as it is ruined, sometimes.
> also seems the data file would be much larger than necessary due to
> the formatting,
> <FirstName>Fred</FirstName>. Twenty tree characters to store �Fred�.
> Or, <TimeZone>CST</TimeZone>, twenty characters to store �CST�.
One of my biggest problems with XML too. Also, good luck on standardizing the XML tags for your "universal" file format... :)
Paul Tiseo, Systems Programmer
Research Computing Facility, Mayo Clinic tiseo128.paul23_at_mayo.edu
(please remove numbers to email me) Received on Mon Jul 14 2003 - 22:32:07 CEST