XML vs. SQL

[Cooper, Ben]

Dear Roger,
The key benefit of XML is that it is a self-describing open format that is
human readable.  It is text data that is stored in flat text files,
requiring no proprietory file formats that might go out-of-date in time.
XML has been developed from SGML, a data format that has been developed and
proven over a perioed of more than 30 years.

SQL is not a storage format, but a query language for relational data.  To
say that data is stored in a relational database actually tells you nothing
about the storage format - remember that when Informix started out, they
stored their relational databases in ISAM (indexed sequential access method)
files, and today Oracle uses a number of different physical data formats.

However, most database vendors are providing XML parsers for their
databases, so once cave data is in XML format, it can easily be loaded into
relational databases for particular projects.  However, for long-term
archiving (and for data exchange) XML is what should be used.  

Regards,
Ben Cooper
Systems Architect, Siemens Business Services
Tel: 01344 850 539  (this number diverts to my mobile)
Fax: 01344 358 489


> -----Original Message-----
> From: Roger Schuster [mailto:roger@r-schuster.de]
> Sent: 10 January 2001 13:50
> To: cave-surveying@survex.com
> Subject: XML vs. SQL
> 
> 
> Hello cavers,
> 
> following the recent discussion I got the impression that most cavers 
> favorite a cave survey data format which is derived from XML 
> or another 
> type of markup language. I think XML isn't the "silver 
> bullet" that can 
> solve all problems and can be used for storing any kind of data. For 
> exchanging data XML is good but poor for everyday work. 
> 
> What's about storing data in a SQL data base? A SQL data base 
> has this 
> advantages: 
> 
> - Lots of data bases are freeware or even open source products so you
>    can use them free of charge, e.g. ADABAS, Interbase, SAP 
> DB,  MySQL,
>    PostgreSQL etcetera. 
> - Most of them are available for several operating systems.
> - SQL is as well as XML an industry standard.
> - Lots of ODBC / JDBC drivers are available and ready for production.
> - SQL servers are ready for network computing. Today many cave 
>    expeditions have participants from around the globe so 
> that working 
>    with shared and distributed resources is important. 
> - SQL is fast.
> - And now the most important: SQL is flexible and easy to 
> use. Even on 
>    the text console only a few lines of code are enough to do complex 
>    data base queries. You can put many different types of data in
>    different data base tables and join, sort and re-organize them on
>    the fly in any way you want. For example you can put the 
> survey raw 
>    data in a table and geological data in another table and merge 
>    them together. In XML you either produce a large and complicated 
>    text file with a huge amount of additional data or you have to 
>    fiddle around with several files. Probably the user must 
> write his /
>    her own tools to read, convert and process the additional data. In 
>    SQL this is an easy task with standard query commands.
> 
> My 0.2 Euro, any comments? 
> 
> Roger
> 
> 
> 
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