• Large documents are compressible.
  • Applying XML
  • General Uses of XML: Making Database Information Available on the Web
    		•

    Virtually unlimited scalability




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    Ceponkus, Hoodbhoy - Applied XML - Toolkit for Programmers

    Virtually unlimited scalability.
    It’s built into the name. XML documents are extensible 
    and let you include as much markup information as you want, so you can code in any 
    extra information you want the client/application to know. This prevents the server from 
    having to be pinged repeatedly to get all the necessary information. Also, because of the 
    granular update ability mentioned above, the server’s scalability implicitly increases 
    because it has less work to do.
    Large documents are compressible.
    HTTP 1.1 includes the specifications for 
    compression of information that translate really well with XML. Because typical XML 
    documents consists of repetitive tags, they can be compressed fairly easily. (If you’re not 
    familiar with compression algorithms, repetitive entities are really easy to compress.) This 
    is probably more interesting to you if you transfer large amounts of data over the Web so 
    you can take advantage of the repetitive nature of XML elements. For smaller transfers, 
    the results are less remarkable and are about the same fat (uncompressed) kilobyte for 
    fat kilobyte as HTML transfers.
    If you’re still not convinced, let’s look at where XML is, can, and will be applied.
    Applying XML
    By now your interest in XML may be piqued but you may not still be clear on where and 
    how XML fits in. Allow us to present some scenarios—some general, some specific, 
    some hypothetical, and some real—with their general XML-based solution outlines. By 
    the way, the hypothetical ones are free potential seeds for business ideas.
    General Uses of XML: Making Database Information Available 
    on the Web
    The following outlines a business scenario and then provides the XML solution.

    - 34 -
    Problem/Scenario
    One of the first things you learn when you get into information systems is how wonderful 
    database systems are and how many wonderful opportunities abound by using the 
    Internet to interface with your database. One of the last things people mention is how 
    hard it is to translate information back and forth between the two. There is currently no 
    standard way of marrying the Internet to existing databases. Sure, there are plenty of 
    custom solutions that involve many, many lines of code in the form of CGI (common 
    gateway interface) scripts, but there isn’t a really standardized way of making an SQL 
    query and generating a report over the Internet. Furthermore, once you’ve generated the 
    query, the results that come back to you are not necessarily the most useful. Sure they 
    may be in a pretty HTML page, but then what? How do you export that data into Excel or 
    some other package for further processing? Cutting and pasting is an option, but it is 
    cumbersome and irritating and scales very poorly with larger data sets. Figure 2.10 
    illustrates this problem.

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