EXI (efficient XML interchange) coming... Are XML APIs ready?

Question

W3's EXI (efficient XML interchange) is going to be standardized. It claims to be "the last binary standard".

It is a standard to store XML data optimized for processing and storage, is bundled with XML schema (making the data strongly typed and strongly structured). Well, there are a lot of claimed advantages. I was impressed most by the processing and memory-efficiency measurements.

I am asking myself, what is going to happen to all the established XML APIs?

There is this paragraph related to my question:

4.2 Existing XML Processing APIs

As EXI is an encoding of the XML Infoset, an EXI implementation can support any of the commonly-used XML APIs for XML processing, so EXI has no immediate impact on existing XML APIs. However, using an existing XML API also requires that all names and text appearing in the EXI document be converted into strings. In the future, more efficiency might be achievable if the higher layers could directly use these data as typed values appearing in the EXI document. For instance, if a higher layer needs typed data, going through its string form can produce a performance penalty, so an extended API that supports typed data directly could improve performance when used with EXI.

from: http://www.w3.org/TR/exi-impacts/

I understand it as following: "Using EXI with existing APIs? No performance gain! (Unless you rewrite them all)"

Let's take the Java ecosystem as an example:

We have plenty of XML APIs in latest JDK 6 (With each major JDK release, more and more of them were added.) As far as I can judge, most (if not all) of them are using either in-memory DOM trees, or serialized ("textual") representation to transform/process/validate/... XML data.

What do you guys think, what is going to happen to these APIs with introduction of EXI?

Thank you all for your opinions.

For those who don't know EXI: http://www.w3.org/XML/EXI/

Answer 1

You don't need any new APIs to get the performance gains of EXI. All the EXI testing and performance measurements the W3C has conducted use the standard SAX APIs built into the JDK. For the latest tests, see http://www.w3.org/TR/exi-evaluation/#processing-results. EXI parsing was on average 14.5 times faster than XML in these tests without any special APIs.

One day, if people think its worthwhile, we may see some typed XML APIs emerge. If and when that happens, you will get even better performance from EXI. However, this is not required to get excellent performance like that reported by the W3C.