Online SQL schema migration examples

This document links to several examples implementing online SQL schema migrations to facilitate simultaneously running OpenStack services in different versions with the same DB schema.

• Nova data migration example
• Nova data migration enforcement example of sqlalchemy migrate/deprecated scripts
• Nova flavor migration spec example of data migrations in the object layer
• Cinder online schema upgrades spec example of migrating a column to a many-to-many relation table

For documentation on how to make online migrations move on to Database Schema Migrations.