ios - Firebase as distributed database sync engine for invoices, with disconnect? -

i'm building invoice app ios. need way sync data between several devices of same company use app. have common customers, product, inventory, invoices/detail tables.

i wonder if firebase suitable this.

mainly, main concern ios devices need operate disconnected time (up 1 day, people work in locations poor or non-existent communication).

my second concern customers use pos, , generate large amounts of invoices, same company group. app used small supermarkets , wholesale distributors, reason travel , stay in local.

for of it, think firebase closer solution (i'm considering pusher, parse , pubnub) because have copy of data , become "database master" of this.

i have think in have central postgress database database master, maybe unnecesary firebase?

i started working firebase year ago after going facebook hackathon in austin. instantly fell in love system , don't have enough things it. benefits firebase obvious, can daunting use such new system sensitive information.

1). if firebase disconnects websocket, stores information , once socket reconnected, wills end of information. wonderful , has saved quite bit of headache.

2). handles large amounts of data well. i'm not 100% sure follow question, sounds want ensure can transfer/store large amount of data. while never had send ton of data @ once, have pulled in large amounts (half gig of text) , had no real issues (a bit slow reporting, can't avoided).

3). if want store information locally well, can pass info firebase via backend can ping server (ie: curl).

also, 1 of awesome things firebase introduced couple months ago validation (so no 1 can ping firebase , tell them drop info without being validated). uses read/write privileges easy set up.

let me know if have more questions it