Storing models for cheap on Factom about 0xdeca10b

[juharris]

Thanks for your interest in this project! That's a good suggestion. Storing lots of data in Ethereum isn't ideal but I have some concerns with other storage methods. Maybe you already saw my FAQ about it: https://github.com/microsoft/0xDeCA10B#what-about-storing-models-off-chain ?
I've looked into Factom a bit and some of those concerns might apply to Factom as well. The information on their site was vague. Here are some questions for my notes or you to answer if you happen to know the answers:

1. Is it cheap to update data? Factom advertises that data is immutable but if I can efficiently update a model then that might be good to do rather than storing a new model for every update.
2. We might have to use an oracle to get the model if it is stored externally, this cost might be too high for some models.
3. Is the data storage persistent? A peer-to-peer network is mentioned and if it is like IPFS, then it's not reliable.