What if pt-online-schema-change would be use simultaneously?

Hello everyone!

This is my first post in the Percona’s community, so please take it easy with me :rolleyes:

My question is very simple: [CENTER]What if pt-online-schema-change is used simultaneously?[/CENTER]

I read from the docs the following:

The thing is, I’m building a web application which may require the creation of new columns in the database schema… so I thought that making this tool accessible via web service was my salvation!
But… what could happen if two (or even three! :eek:) users execute the web service simultaneously?

Thank you very much for you time! :slight_smile:


It depends though I would like to check, do you have any triggers on tables/db? Because the table (or tables) being altered can not have any triggers; pt-osc wants to be the only thing that puts triggers on a table. If triggers aren’t a problem, then I dont think there should be any “concurrency” issues. I have bit doubt for foreign keys.

I would suggest you should try to run it on test/stage servers and let us know if you are facing any issue.

Hi nijoshi,

thank you for the response. I don’t have any triggers configured in the tables that I want to alter, so good news for me.

I’m going to test it though in a couple of days and will post the results here.

Thank you again!