Open Stack

Hi.

Because I am a grumpy old man I have just -2'ed
https://review.openstack.org/#/c/39685/ and I wanted to explain my
rationale. Mostly I am hoping for a consensus to form -- if I am wrong
then I'll happy remove my vote from this patch.

This patch does the reasonably sensible thing of converting two
columns from being text to varchar, which reduces their expense to the
database. Given the data stored is already of limited length, it
doesn't impact our functionality at all either.

However, when I run it with medium sized (30 million instances)
databases, the change does cause a 10 minute downtime. I don't
personally think the change is worth such a large outage, but perhaps
everyone else disagrees.

Discuss.

Thanks,
Michael

PS: I could see a more complicated approach where we did these changes
"in flight" by adding columns, using a periodic task to copy data to
the new columns, and then dropping the old. That's a lot more
complicated to implement though.

-- 
Rackspace Australia