Is there any way to avoid delay for getting data when high speed internet connection available?(no delay if it there is no internet connection) - google-cloud-firestore

Question

I have 100 documents
Document id
0001
0002
0003
....
....
0100
and if we load 5 documents with id 001,002,004,005,006
then firestore charge for 5 document reads and then we again load(call the read operation query) documents with id 004,005,006,007,008,001,002
then firestore will charge for 7 document reads
here on first time we already loaded document with ids 001,002,004,005,006 and in second time or refresh time we are loading documents already loaded and some new documents
Here we need to avoid multiple times reading document from server and read it from cash and need to avoid the firestore over document read charges How to do it?
Firestore have cash loading option but it will only load from cash and not from server here what we need is load exiting data from cash and load remaning data form server.Here now what firestore doing is it will load from server and if it is failed then it will read from cash that is ok but i need in revise order
Now what happening is if non internet all data load faster with out showing progress and if there is internet it will take few sec to load and it will shows loader When we do it without fireabase our app will shows loading only one time then first it will shows the data from sqlite then when ever the api call resoppnce reached we will update in ui, so users will not face any loader but with firestore user need to wait for a progress bar to finish

Answer 1

From a first glance it seems that you may use firebase firestore caching for this use case. This can be done easily for example in JS:
documentRef.get({ source: 'server' }) // or 'cache'
this will indeed reduce costs however it may read always from your local cache and never reach the server for new changes in your document. This might be what you want but it seems practical only if your documents (immutable) and never change. so you will be able to read new documents but if they change you might not see the changes. Please, read more about this here
A better suggestion is to change your app logic. So, rather than reading the documents this way:
001,002,004,005,006
004,005,006,007,008,001,002
it's better to read them in a paginated way like this:
001,002,003, 004,005,006
007,008,009,010,011,012
You can achieve that easily by using the concept of pagination in Firestore:
var first = db.collection("cities")
.orderBy("population")
.limit(25);
return first.get().then(function (documentSnapshots) {
// Get the last visible document
var lastVisible = documentSnapshots.docs[documentSnapshots.docs.length-1];
console.log("last", lastVisible);
// Construct a new query starting at this document,
// get the next 25 cities.
var next = db.collection("cities")
.orderBy("population")
.startAfter(lastVisible)
.limit(25);
});
check Firestore documentation for more details