Ways to handle huge XML/JSON files

[qwerty150]

I'm looking to create an Android (altho for iOS the problem will be the same) application which will function pretty much as a webshop. It will contain a lot of products - which can be acces through any way we want since that still has to be build. The problem is, we created a plain text file to test the size, and it turns out that even a selection of the products, with no structure (XML, JSON..) is already 300mb. Once we add a structure, this will logically only cause more overhead and increase this size. Like I said, pretty much anything is possible in matters of receiving the data.They can build an API to be able to fetch products once at a time when needed, or 1 big file to parse in a background process... However, one of the wishes is being (as much as possible) offline. This would normally mean saving all the data into a database on the phone, but if this will result in 300mb on your SD card, this is no good. To sum it up what I exactly want to know;Are there any other ways to handle big data like this, without having to keep a connection to internet constantly, or having to download 300mb on someone's phone. Some kind of compression, special way to save it in the database... any ideas are welcome.