Batch writes

We gather writes in a batch object and ask Firebase to perform (commit) all the writes at once.

The operation is atomic: if one write fails, the others fail as well. This prevents a broken state where only some documents are updated.

A single network request is sent.

Note: the functions are namespaced on batch both for the client SDK and the admin SDK.

batch changes then commit

Collect up to 500 writes in a batch object, and execute them with commit().

In this example, we use update(), but we could also use set() or other methods.

const batch = writeBatch(db)
// const batch = db.batch() // admin SDK

const change = { timezone: "Europe/London" }

batch.update(docRef1, change)
batch.update(docRef2, change)
// ..
// ..

await batch.commit()

other batch operations

batch.set(docRef, data)
batch.set(docRef, change, { merge: true })
batch.update(docRef, change)
batch.delete(docRef)
batch.create(docRef, data) // Admin SDK