Firestore collection subscription pricing

Viewed 148

If I'm subscribing to a collection that has 1000 docs, will I bee charged for 1000 reads as soon as the subscription is initiated? Per https://firebase.google.com/docs/firestore/pricing#listens I'd say no, but per https://stackoverflow.com/a/60356400/9118098 I'd say yes.

I'm asking as I have an "ever-growing" calendarEvents collections, and am trying do decide whether it'd be better to structure data as

calendarEvents/{calendarEventId}

or

calendarEvents/{2022}/March/{calendarEventId}

to keep the cost down, as the latter allows me to subscribe to the current month only.

1 Answers

If by subscription you mean Firestore listeners then you are charged based on the number of document retrieved by the listener.

For example, your collection has 1000 documents and you add a listener on the whole collection then you'll be charged 1000 reads for those documents and 1 read for each subsequent update received. If you add some query clause such as where(field, "==", value) and let's say this matched and returned only 700 documents, then you'll be charged 700 reads for initial read and 1 for each update received.

Related