Large Data Service (Astoria) payloads: How to improve performance?

Question

I have a silverlight client accessing data through ado.net data services. One of my queries has a number of expand clauses, and gets back quite a number of entries. The xml response is enormous, and I'm looking for ways to make this more efficient.

I have tried:

• Paging (not an option for this behaviour)
• Http compression (some client pcs are running IE6)
• Doing the expands as separate queries and joining the entities later (this improved things a little)

Is it possible to use JSON as a transport format with the silverlight client? I haven't found anything about this on the web...

Answer 1

You can see the demonstration of using JSON in silverlight in the below link

http://timheuer.com/blog/archive/2008/05/06/use-json-data-in-silverlight.aspx

I am not sure how much performance gain is achieved by using JSON. I definitely remember that ado.net services does JSON.

Answer 2

Well. I got a chance to talk to Tim Heuer about this, who awesomely went and asked Pablo Castro for me. Thanks Tim!

JSON can't be used by the Silverlight client, but Silverlight 3 will be using binary xml by default to talk to web services. Rawr.

One other thing i worked out for myself was that using expand can sometimes result in a lot more data than performing multiple requests. If you batch a few queries together and then hand-stitch the objects together, you can save quite a bit of xml.