This is true, but note that the article was written in the context of PostgreSQL instead of MySQL. PostgreSQL can do many types of table migrations with no dow

This is true, but note that the article was written in the context of PostgreSQL instead of MySQL. PostgreSQL can do many types of table migrations with no downtime (dropping columns, renaming, adding columns that default to NULL, and creating indexes). Before I made the switch from MySQL to Postgres I did some quick benchmarks which support these claims on a 5 million row test table: https://gist.github.com/1620133 https://gist.github.com/1620133.