[zmoazeni]

No. https://githubengineering.com/gh-ost-github-s-online-migrati... has an excellent section on why triggers fail (at least in the MySQL world. I imagine the locking story is similar in postgresql).

I don't work for GitHub but we had the same problems using pt-online-schema-change independently of their issues (lots of locking contention affecting the app negatively). We're finally moving to gh-ost for our large/risky migrations and so far it's amazing.