Handling large database changes in OpenMRS

[mogoodrich (Mark Goodrich)]

I can work with others to pull this into a better place, but for immediate reference I wrote up more about what I did here:

Challenges with large data during platform upgrade

We’ve confirmed that 4 of the 5 changesets (the ones that ADD and DROP) can be run “online” without locks in MySQL 5.6 (though they still take about an hour each to run), with one caveat… if your database was originally created with a version of MySQL prior to 5.6, the first change will need to lock and copy the entire table, at which point it will be updated to 5.6. The changeset that alters the value_complex requires a full column copy and can take take 1-2 hours to run… it reading the docs i…