RE: [xml-dev] Is it time for the binary XML permathread to start up aga

[Alessandro Triglia <sandro@mclink.it>]

Hi Roger,

Here are a few points.

- Zip, Fast Infoset, or EXI can be used with any XML document

- Zip reduces the size of the document on the wire but usually increases processing time

- ASN.1 requires that the two endpoints share a schema that describes your XML document; the schema can be either an original ASN.1 schema (one originally written in ASN.1 notation), or one that has been automatically derived from an XSD schema through the standard X.694 mapping; in addition, ASN.1 requires that your XML document be completely valid (it doesn’t tolerate deviations from the schema); if your application uses schemas and does not need to support anything other than valid XML documents, then ASN.1 BER/PER can be a good choice because it's very fast and compact

- Fast Infoset, which does not depend on schemas, usually achieves good compactness and acceleration effortlessly, but its performance can be improved (especially for short documents) if the sender of the XML document has some (a-priori) knowledge about the document (e.g., partial or total conformance to a certain schema, or even just some statistical properties of the XML document, for example a list of expected frequent element names or attribute values or namespace URIs);  in most cases, performance improvements can be achieved without any requirement that the receiver know anything about the document before receiving it, but Fast Infoset also supports the use of an external vocabulary (to be shared among the participants) in order to further improve performance

- I believe some of the things I wrote above about Fast Infoset apply to EXI as well

Alessandro



Costello, Roger L. wrote:
> When sending an XML document across the wire, here are the main
> choices:
>
> 1. Send the XML document as is, as ASCII text, without any compression 
> or other alterations.
>
> 2. Compress the XML document using a compression tool such as WinZip 
> or Bzip, and then send the compressed document.
>
> 3. Encode the XML document as an ASN.1 file, and then send the ASN.1 
> file.
>
> 4. Encode the XML document a Fast Infoset file, and then send the FI 
> file.
>
> 5. Encode the XML as an Efficient XML Interchange file, and then send 
> the EXI file.
>
> Are there other choices?  Have I phrased each choice properly?
>
> Under what circumstances would a choice be selected? 
>
> What are the advantages and disadvantages of each choice?
>
> /Roger
>