Question

I am developing a little app that retrieves an XML file, located on a remote server (http://example.com/myfile.xml) This file is relatively big, and it contains a big list of geolocations with other information that I need to use for my app. So I read this file remotely once and insert it into a little SqlCE file (database.sdf)

So If I need to be accessing geolocation #1, I ll just make a SELECT statement into this DATABASE instead of loading the whole XML file every time.

But I would like to know if its possible to do this without using .sdf files?

What is the most efficient way (fastest)?

Saving the big XML file once locally and load if every time I start my app to load it in a data set? this is would make the app a bit long to load every time

Saving the big XML file once locally and reading the nodes one by one to look for geolocation #1?

Or is it possible to retrieve geolocation #1 from the remote XML directly(http://example.com/myfile.xml) without reading the whole file?

Answer 1

Re protobuf-net, there isn’t a separate download for the CF version at the moment, but there is a csproj in the source for both CF 2.0 and CF 3.5.

To clarify on your question; actually protobuf-net doesn’t even use a .proto file (at the moment); a .proto file just describes what the data is – protobuf-net simply looks at your classes and infers the schema from that (similar to how XmlSerializer / DataContractSerializer etc work). So there is not .proto – just the classes that look like your data.

However, before you embark on creating classes that look like your data, I wonder if you couldn’t simply use GZIP or [PK]ZIP to compress the data, and transfer it "as is". XML generally compresses very well. Of course, finding a GZIP (etc) implementation for CF then becomes the issue.

Of course, if you want to use protobuf-net here, I’ll happily advise etc if you get issues…

The other option is for your CF app to call into a web-service that has the data locally…