Re db migrations: they've built their own DB management tooling (https://github.com/openark/orchestrator https://github.com/openark/orchestrator) and online mig

Re db migrations: they've built their own DB management tooling (https://github.com/openark/orchestrator https://github.com/openark/orchestrator) and online migration tooling (https://github.com/github/gh-ost https://github.com/github/gh-ost)