migration-helper

To run zero-downtime schema migrations in Convex, apply additive changes first, then implement internal mutations to backfill existing data in batches. This migration-first workflow with guardrails ensures continuous availability while updating your schema.

A migration-first workflow for backfills separates schema evolution from data transformation by deploying optional fields first, running batch processing mutations to update records, and enforcing guardrails. This safely manages breaking changes during data migration.

Adding a required field to an existing Convex table requires an additive migration: deploy the field as optional, run a backfill mutation to populate existing records, then apply the required constraint. This avoids breaking changes during schema evolution.

Yes, this approach handles breaking changes and cross-environment deployment through code-driven migrations. It provides internal mutations and scripts to safely perform data transformations and ensure zero-downtime rollout across different environments.

You need batch processing for data migrations when transforming large datasets to prevent system overload. Processing records in chunks during a backfill ensures zero-downtime updates and maintains application performance throughout the schema evolution.