migration-planner

A zero-downtime database migration uses phased deployments and rollback strategies to apply schema changes without taking the application offline. This involves generating ordered migration scripts that handle data backfills and schema diffs safely across staging or production environments.

A schema diff identifies the differences between your current and desired database schemas. This diff is used to generate UP and DOWN migration scripts, allowing you to apply changes and safely revert them if needed during a database migration.

To backfill data when adding a nullable column, you generate a migration script that adds the column with a default value, populates the existing rows, and switches reads. This phased deployment ensures zero-downtime during the database schema migration process.

Yes, you can generate both UP and DOWN migration scripts by analyzing the schema diff. The DOWN script provides a rollback strategy to revert the schema change and any associated data backfills if the production deployment encounters issues.

You need the current schema, the desired schema, the database type, and your risk tolerance. This information is used to generate ordered migration scripts, data backfill procedures, and a rollback plan tailored to your production or staging environment.

You should use a phased deployment for a database schema migration when you need zero-downtime updates in production. This approach safely applies schema diffs and data backfills incrementally, ensuring you can execute a rollback strategy if necessary.