I am looking for a Zero-downtime Database Migration tool that would provide:

- Migration of data from one version of the application to another version with or without changes to the database schema.

- Migration of data from staging to production where staging was used for beta testing to host customers who created live data which need to be migrated to production. (SQL Server 2005 to SQL Server 2005, SQL Server 2005 to MySQL)

- if a data type changes (say int to varchar) in staging database for a particular column in a table, the change migration should happen in the production database as well

- if a column is added\deleted in a table of staging database, the same table alteration should migrate to production database

- records in production database should not be deleted\truncated during data\schema migration

- demonstrate zero-downtime

Please let me know if you are aware of a tool that provides such features.