Google Cloud Firestore: notes and links

Documentation

Notes from videos:

max 1 MB of data in a single document
max 20k of fields in a single document (including maps)
1 write/second on a single document
can't retrieve a partial document
queries are shallow by default
billed by the number of reads and writes performed (2m read requests = $.12)
queries find documents in single (sub)collection
arrays are weird
you can't run 2 "array contains" queries on the same array
There's a limit to how many documents you can create per minute in a single collection if the documents have an always-increasing value (like a timestamp)
Very large collections don't do as well from a performance standpoint when you're offline.

Notes from docs:

Querying across multiple subcollections is not currently supported in Cloud Firestore. (collection group query). If you need to query data across collections, use root-level collections.*
Array: An array cannot contain another array value as one of its elements. Map: Represents an object embedded within a document. When indexed, you can query on subfields. If you exclude this value from indexing, then all subfields are also excluded from indexing.*
Cloud Firestore automatically maintains an index for each field in a document and each subfield in a map. Exempt from auto-indexing: large string/array/map fields, timestamps.*
You also get full query capabilities on subcollections (individual, not multiple).*

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash

sudo npm cache clean -f
sudo npm install -g n
sudo n stable

3) Install Java JDK (JRE is not enough)

npm install -g firebase-tools
firebase login

firebase setup:emulators:firestore

npm install @firebase/testing

firebase serve --only firestore